CINXE.COM

9 of the World’s Deadliest Spiders | Britannica

<!doctype html> <html lang="en" class="list-desktop ui-ie7 ui-ie"> <head prefix="og: https://ogp.me/ns# fb: https://ogp.me/ns/fb#"> <meta charset="utf-8"> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /> <meta name="viewport" content="width=device-width, initial-scale=1.0" /> <link rel="dns-prefetch" href="https://cdn.britannica.com/mendel-resources/3-130"> <link rel="preconnect" href="https://cdn.britannica.com/mendel-resources/3-130"> <link rel="preload" as="script" href="https://www.googletagservices.com/tag/js/gpt.js" /> <link rel="icon" href="/favicon.png" /> <meta name="description" content="This Encyclopedia Britannica list introduces 9 dangerous and deadly spiders." /> <meta name="keywords" content="encyclopedia, britannica, encyclopedia britannica, list, lists, dangerous, deadly, spiders, arachnids, black widow, wolf spider, animals, bugs, insects" /> <link rel="canonical" href="https://www.britannica.com/list/9-of-the-worlds-deadliest-spiders" /> <title>9 of the World’s Deadliest Spiders | Britannica</title> <script type="text/javascript" data-type="Init Mendel"> window.$UI = {}; window.Constants = {"LICENSE_URL": "/bps/license","DEFAULT_TEST_VERSION": "A","DEFAULT_STATE": "XX","QUIZ_URL": "/quiz","SPOTLIGHT_BROWSE_URL": "/stories/spotlight","CONTENT_TYPE_TEXT": "text/plain;charset=UTF-8","TOPIC_FACTS_DATA_URL": "/facts","QUIZ_BROWSE_IMAGE_QUIZZES": "images","TOPIC_MEDIA_PATH": "/images-videos","USER_PROFILE_URL": "/user","DEBUG_URL": "/debug","ONE_GOOD_FACT_URL": "/one-good-fact","ERROR_404_URL": "/error404","PROCON_CITED_IN_THE_NEWS_URL": "/procon/ProCon-in-the-News","PROCON_URL": "/procon","TOPIC_PAGE_CONTENT_AJAX_URL": "/topic-content/page","INFINITE_SCROLL_PREFIX_URL": "/scroll","TOPIC_TOP_QUESTION_BROWSE_URL": "/questions","CC_USD": "USD","domain": "britannica.com","SURVEY_URL": "/survey","CATEGORY_BROWSE_URL": "/browse","STORY_BROWSE_URL": "/stories","COUNTRY_US": "US","OPEN_MEDIA_OVERLAY_PARAMETER": "/media","NEWSLETTER_SUBSCRIPTION_URL": "/newsletter-subscription","MAINTENANCE_ERROR_URL": "https://maintenance.eb.com","IMARS_EDITOR_ID": "12365882","PROFILE_EB_EDITOR_URL": "/editor","WEB_INF_RESOURCES_PATH": "WEB-INF/resources","AI_ABOUT_PAGE_URL": "/about-britannica-ai","TOPIC_ADDITIONAL_INFO_PATH": "/additional-info","SUDOKU_GAME_URL": "/games/sudoku","CC_INR": "INR","ARTICLE_PRINT_URL": "/print/article","FIRST_EDITION_URL": "/subscriber/firstedition","WW1_PORTAL_URL": "/discover/World-War-I","MENDEL_COOKIE": "__mendel","DEMYSTIFIED_BROWSE_URL": "/stories/demystified","LIST_BROWSE_URL": "/list/browse","PROFILE_EXPERT_URL": "/contributor","ASSEMBLY_IMAGE_URL": "/image/assembly","DAY_IN_HISTORY_URL": "/on-this-day","DEFAULT_CURRENCY": "USD","CONTENT_TYPE_XML": "text/xml;charset=UTF-8","PORTAL_FINANCE_BROWSE_URL_PREFIX": "/money/browse","MONEY_IMARS_CATEGORY": "13000","AJAX_PREFIX_URL": "/ajax","TOPIC_BROWSE_URL": "/topic-browse","MARKETING_CONTENT": "/marketing-content","ENV_RUNTIME": "runtime","GALLERY_URL": "/gallery","topicUrlClassesList": "topic|animal|art|biography|event|place|plant|science|sports|technology|procon","CONTENT_TYPE_HTML": "text/html;charset=UTF-8","ENV_LOCAL": "override","MEDIA_OVERLAY_URL": "/media-overlay","CHATBOT_PAGE_URL": "/chatbot","NEWSLETTER_PAGE_URL": "/newsletters","ENV_DEV": "development","MEDIA_URL": "/media","TOPIC_TOP_QUESTION_URL": "/question","PORTAL_FINANCE_URL_PREFIX": "/money","PODCASTS_URL": "/podcasts","STAND_ALONE_VIDEO_URL": "/video","MORE_ON_THIS_DAY_URL": "/more-on-this-day","TOPIC_QUOTES_URL": "/quotes","SEARCH_PAGE_URL": "/search","PROCON_CLASS": "PROCON","KUSTOM_MENDEL_APPLICATION_ID": "1","TOPIC_CONTENT_AJAX_URL": "/topic-content/topic","ENV_BRANCH": "branch","ERROR_URL": "/error","MAIN_VERSION": "mainVersion","DEFAULT_S3_REGION": "US_EAST_1","TOPIC_COLLECTION_URL": "/summary","LOGINBOX_URL": "/auth/loginbox","ONE_GOOD_FACT_BROWSE_URL": "/one-good-fact/all-good-facts","QUIZ_BROWSE_URL": "/quiz/browse","BIO_BROWSE_URL": "/browse/biographies","LIST_URL": "/list","TIGHTROPE_QUIZ_URL": "/quiz/tightrope","ALPHA_BROWSE_URL": "/sitemap","CONTENT_TYPE_JSON": "application/json","DICTIONARY_URL": "/dictionary","COBRAND_IMAGE_URL": "/image/cobrand","PROCON_IN_THE_NEWS_URL": "/procon/pro-and-con-issues-in-the-news","PROCON_BROWSE_URL": "/procon","QUIZ_BROWSE_VOCAB_QUIZZES": "vocabulary-quizzes","SUBMISSION_URL": "/submission","EB_LOG_OUT": "/auth2/logout","ENV_PRODUCTION": "production","EXPLORE_PORTAL_URL": "/explore","TOPIC_AJAX_URL": "/ajax/topic","TOPIC_SUMMARY_BROWSE_URL": "/summaries","WTFACT_BROWSE_URL": "/stories/wtfact","VIDEO_CHANNEL_URL": "/videos","GALLERY_BROWSE_URL": "/gallery/browse","CACHE_URL": "/cache","PROCON_ABOUT_URL": "/procon/About-ProCon","COMPANION_BROWSE_URL": "/stories/companion","MEDIA_FOLDER": "/eb-media","SHOW_ALL_CONTRIBUTORS": "/additional-info#contributors","BRITANNICA_EDITORS_ID": "4419","ENV_CACHE_DISABLED": "mendelCache","CALCULATORS_BROWSE_URL": "/calculators","STORY_URL": "/story","DEFAULT_COUNTRY": "US","NAVBAR_URL": "/ajax/navbar","EB_LOGIN_URL": "/auth/eb-login","NEW_ARTICLES_URL": "/new-articles",}; window.CDN = "https://cdn.britannica.com"; window.CAM_LOGIN_URL = "https://cam.britannica.com"; window.CAM_SIGN_UP_URL = "https://cam.britannica.com/registration" window.Mendel = { "config" : { "domain": "britannica.com", "page": "List", "videoPlayerId": "UyMCoK2v", "sharedUrl": "https://www.britannica.com/list/9-of-the-worlds-deadliest-spiders", "amuselabsUrl": "https://cdn3.amuselabs.com", "resourcesPrefixUrl": "https://cdn.britannica.com/mendel-resources/3-130/[url]?v=3.130.14", "date": 20241203, "userInfo": { "type": "ANONYMOUS" ,"currency": "AUUS" ,"country": "SG" ,"state": "XX" ,"timezone": "Asia/Singapore" ,"bcomId": "-4865892429234303845" ,"hasAds": true ,"testVersion": "B" ,"adsTestVersion": "B" ,"consumerId": "" ,"instId": "" ,"consumerUserName": "" ,"instUserName": "" ,"cognito": null }, "tvs":{ "r":[25,25,25,25], "a": [25,25,25,25]}, "isLoggedInAsUser": false, "isPhone": false, "isDesktop": true, "logoutUrl": "/auth2/logout", "selfServiceUrl": "https://myaccount.britannica.com", "cdnUrl": "https://cdn.britannica.com", "chatbotApi": "https://www.britannica.com/chat-api", "fetchOffset": 800, "mendelCookieName": "__mendel", "mendelCookie": {"surveyShown":false,"visitedTopicId":0,"currentDate":20241203}, "autocompleteToSearchPage": false,"listId": 3793 ,"pagesInfo": [{"url":"9-of-the-worlds-deadliest-spiders","title":"9 of the World’s Deadliest Spiders"},{"url":"10-famous-artworks-by-leonardo-da-vinci","title":"10 Famous Artworks by Leonardo da Vinci"},{"url":"7-wonders-of-america","title":"7 Wonders of America"},{"url":"10-best-sports-rivalries-of-all-time","title":"10 Great Sports Rivalries"},{"url":"9-of-the-worlds-deadliest-snakes","title":"9 of the World’s Deadliest Snakes"},{"url":"9-of-the-worlds-deadliest-mammals","title":"9 of the World’s Deadliest Mammals"},{"url":"6-lost-civilizations","title":"6 Lost Civilizations"},{"url":"7-everyday-english-idioms-and-where-they-come-from","title":"7 Everyday English Idioms and Where They Come From"},{"url":"9-noteworthy-bog-bodies-and-what-they-tell-us","title":"9 Noteworthy Bog Bodies (And What They Tell Us)"},{"url":"7-vestigial-features-of-the-human-body","title":"7 Vestigial Features of the Human Body"}] }, "GA": {"leg":"B","adLeg":"B","userType":"ANONYMOUS","pageType":"List","gisted":false,"pageNumber":1,"hasSummarizeButton":false,"hasAskButton":false} }; </script> <meta property="fb:app_id" content="1887621861548296"/ <meta name="twitter:card" content="summary_large_image" /> <meta name="twitter:site" content="@britannica" /> <meta name="twitter:image" content="https://cdn.britannica.com/70/62770-131-C97CD1F7/Black-widow-spider.jpg" /> <meta name="twitter:description" content="This Encyclopedia Britannica list introduces 9 dangerous and deadly spiders."/> <meta property="og:type" content="ARTICLE"/> <meta property="og:title" content="9 of the World’s Deadliest Spiders | Britannica"/> <meta property="og:description" content="This Encyclopedia Britannica list introduces 9 dangerous and deadly spiders."/> <meta property="og:site_name" content="Encyclopedia Britannica" /> <meta property="og:url" content="https://www.britannica.com/list/9-of-the-worlds-deadliest-spiders"/> <meta property="og:image" content="https://cdn.britannica.com/70/62770-131-C97CD1F7/Black-widow-spider.jpg" /> <meta property="og:image:type" content="image/jpeg" /> <script type="text/javascript" data-type="init opengraph"> Mendel.openGraph = {"type":"ARTICLE","title":"9 of the World’s Deadliest Spiders","description":"This Encyclopedia Britannica list introduces 9 dangerous and deadly spiders.","imageUrl":"https://cdn.britannica.com/70/62770-131-C97CD1F7/Black-widow-spider.jpg","imageType":"image/jpeg","pageUrl":"https://www.britannica.com/list/9-of-the-worlds-deadliest-spiders"}</script> <link rel="preconnect" href="https://fonts.googleapis.com/"> <link rel="dns-prefetch" href="https://fonts.googleapis.com/" > <link rel="stylesheet" href="https://fonts.googleapis.com/icon?family=Material+Icons"> <link href="https://cdn.britannica.com/mendel-resources/3-130/dist/vendor-bundle.css?v=3.130.14" rel="stylesheet" /> <link href="https://cdn.britannica.com/mendel-resources/3-130/dist/mendel-css.css?v=3.130.14" rel="stylesheet" /> <link href="https://cdn.britannica.com/mendel-resources/3-130/dist/list-page.css?v=3.130.14" rel="stylesheet" /> <script type="text/javascript"> if (self !== top) { top.location = self.location; } // if ('scrollRestoration' in history) { history.scrollRestoration = 'manual'; } </script> <script src="https://cdn.britannica.com/mendel-resources/3-130/js/at.js?v=3.130.14" async ></script> <script> dataLayer = []; </script> <script type="text/javascript">(function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start': new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0], j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src= '//www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f); })(window,document,'script','dataLayer','GTM-5W6NC8'); </script> </head> <body data-leg="B" class="list-page user-ANONYMOUS user-ads md-desktop leg-bb-ie"> <!--- assertive yield ---> <script>Mendel.config.adProvider='ay';</script> <script async src="https://securepubads.g.doubleclick.net/tag/js/gpt.js"></script> <script> window.googletag = window.googletag || {cmd: []}; googletag.cmd.push(function() { googletag.defineSlot('/15510053/CMP_1x1', [1, 1], 'div-gpt-ad-1709766812090-0').addService(googletag.pubads()); googletag.pubads().enableSingleRequest(); googletag.enableServices(); }); </script> <script async defer src="https://launchpad-wrapper.privacymanager.io/0ccc6fe8-1870-4ad8-b47b-6d029ac116fc/launchpad-liveramp.js"></script> <script async src="https://JRyhoywLYXNLYMAhs.ay.delivery/manager/JRyhoywLYXNLYMAhs" type="text/javascript" referrerpolicy="no-referrer-when-downgrade" ></script><div class="ie-warning d-flex align-items-center align-self-center justify-content-center site-alert bg-orange"> <div> You are using an <strong>outdated</strong> browser. Please <a class="text-white text-underscore" href="https://browsehappy.com/">upgrade your browser</a> to improve your experience and security. </div> </div> <script id="json-navbar-info" type="application/json"> {"topSectionLinks":[{"title":"Ask the Chatbot","url":"/chatbot","navbarId":"CHATBOT"},{"title":"Games & Quizzes","url":"/quiz/browse","navbarId":"QUIZZES"},{"title":"History & Society","url":"/History-Society","navbarId":"HISTORY"},{"title":"Science & Tech","url":"/Science-Tech","selected":true,"navbarId":"SCIENCE"},{"title":"Biographies","url":"/Biographies","navbarId":"BIOS"},{"title":"Animals & Nature","url":"/Animals-Nature","navbarId":"ANIMALS"},{"title":"Geography & Travel","url":"/Geography-Travel","navbarId":"GEOGRAPHY"},{"title":"Arts & Culture","url":"/Arts-Culture","navbarId":"ART"},{"title":"ProCon","url":"/procon","navbarId":"PROCON"},{"title":"Money","url":"/money","navbarId":"MONEY"},{"title":"Videos","url":"/videos","navbarId":"VIDEOS"}],"selectedSuperCategory":{"id":6,"title":"Science & Tech","url":"Science-Tech","description":"Explore science and technology; astronomy; biology; chemistry; earth science; mathematics; physics; technology, agriculture, cars, computers, engineering, industry, inventions, communication","keywords":"astronomy; biology; chemistry; earth science; mathematics; physics; technology, agriculture, cars, computers, engineering, industry, inventions, communication","classId":"SCIENCE","sortOrder":2},"selectedNavbarLink":{"title":"Science & Tech","url":"/Science-Tech","selected":true,"navbarId":"SCIENCE"}} </script> <script id="json-hamburger-menu" type="application/json"> {"britannicaMenu1":[{"title":"Home","url":"/"},{"title":"History & Society","url":"/History-Society"},{"title":"Science & Tech","url":"/Science-Tech"},{"title":"Biographies","url":"/Biographies"},{"title":"Animals & Nature","url":"/Animals-Nature"},{"title":"Geography & Travel","url":"/Geography-Travel"},{"title":"Arts & Culture","url":"/Arts-Culture"},{"title":"ProCon","url":"/procon"},{"title":"Money","url":"/money"}],"britannicaMenu2":[{"title":"Games & Quizzes","url":"/quiz/browse"},{"title":"Videos","url":"/videos"},{"title":"On This Day","url":"/on-this-day"},{"title":"One Good Fact","url":"/one-good-fact"},{"title":"Dictionary","url":"/dictionary"},{"title":"New Articles","url":"/new-articles"}],"browseByCategory":[{"title":{"id":5,"title":"History & Society","url":"/History-Society"},"links":[{"title":"Lifestyles & Social Issues","url":"/browse/Lifestyles-Social-Issues"},{"title":"Philosophy & Religion","url":"/browse/Philosophy-Religion"},{"title":"Politics, Law & Government","url":"/browse/Politics-Law-Government"},{"title":"World History","url":"/browse/World-History"}]},{"title":{"id":6,"title":"Science & Tech","url":"/Science-Tech"},"links":[{"title":"Health & Medicine","url":"/browse/Health-Medicine"},{"title":"Science","url":"/browse/Science"},{"title":"Technology","url":"/browse/Technology"}]},{"title":{"id":3,"title":"Biographies","url":"/Biographies"},"links":[{"title":"Browse Biographies","url":"/browse/biographies"}]},{"title":{"id":1,"title":"Animals & Nature","url":"/Animals-Nature"},"links":[{"title":"Birds, Reptiles & Other Vertebrates","url":"/browse/Birds-Reptiles-Vertebrates"},{"title":"Bugs, Mollusks & Other Invertebrates","url":"/browse/Bugs-Mollusks-Invertebrates"},{"title":"Environment","url":"/browse/Environment"},{"title":"Fossils & Geologic Time","url":"/browse/Fossil-Geologic-Time"},{"title":"Mammals","url":"/browse/Mammals"},{"title":"Plants","url":"/browse/Plants"}]},{"title":{"id":4,"title":"Geography & Travel","url":"/Geography-Travel"},"links":[{"title":"Geography & Travel","url":"/browse/Geography-Travel"}]},{"title":{"id":2,"title":"Arts & Culture","url":"/Arts-Culture"},"links":[{"title":"Entertainment & Pop Culture","url":"/browse/Entertainment-Pop-Culture"},{"title":"Literature","url":"/browse/Literature"},{"title":"Sports & Recreation","url":"/browse/Sports-Recreation"},{"title":"Visual Arts","url":"/browse/Visual-Arts"}]}],"browseByFeature":[{"title":"Companions","url":"/stories/companion"},{"title":"Demystified","url":"/stories/demystified"},{"title":"Image Galleries","url":"/gallery/browse"},{"title":"Lists","url":"/list/browse"},{"title":"Podcasts","url":"/podcasts"},{"title":"Spotlight","url":"/stories/spotlight"},{"title":"Summaries","url":"/summary"},{"title":"The Forum","url":"/stories/the-forum"},{"title":"Top Questions","url":"/question"},{"title":"#WTFact","url":"/stories/wtfact"}],"moreFromBritannica":[{"title":"Britannica Kids","url":"https://kids.britannica.com/","newTab":true}],"menuType":"DEFAULT"} </script> <header id="header" class="bg-navy-dark"> <div class="global-nav-top-bar"> <div class="grid gx-0 h-100 justify-content-between align-items-center container-lg mx-auto p-0 position-relative"> <div class="d-flex align-items-center"> <button class="d-flex align-items-center justify-self-start js-toggle js-toggle-hamburger btn btn-link link-white btn-sm rounded-0 p-10"> <div class="hamburger-tooltip"> <em class="material-icons d-inline-block font-24" id="nav-toggle" data-icon="menu"></em> </div> <em class="material-icons d-inline-block font-24 global-nav-search-icon" id="nav-search-icon" data-icon="search" ></em> </button> <a href="/" class="d-flex align-items-center justify-content-center ml-10"> <img loading="lazy" src="https://cdn.britannica.com/mendel/eb-logo/MendelNewThistleLogo.png" alt="Encyclopedia Britannica" class="global-nav-logo global-nav-logo-left" /> </a> <div class="global-nav-top-search-bar global-nav-top-search-container global-nav-search-container" id="global-nav-top-search-bar"> <form method="get" action="/search" id="global-nav-search" class="md-search-form m-0 global-nav-search-bar-small"> <div class="search-box position-relative col-100"> <label class="sr-only" for="global-nav-search-query">Search Britannica</label> <input name="query" id="global-nav-search-query" placeholder="Search Britannica..." class="form-control form-control-lg rounded-lg font-16 search-query pl-20 pr-70 shadow-sm" maxlength="200" autocomplete="off" aria-label="Search Britannica" /> <button class="search-reset-btn btn btn-link px-10 position-absolute top-0 h-100 d-none" type="reset"> <em class="material-icons" data-icon="close"></em> </button> <button class="search-submit btn btn-link text-blue px-10 position-absolute top-0 right-0 h-100" type="submit" disabled> <span class="sr-only">Click here to search</span> <em class="material-icons search-icon" data-icon="search"></em> </button> </div> </form> </div> </div> <a href="/" class="d-flex align-items-center justify-content-center"> <img loading="lazy" src="https://cdn.britannica.com/mendel/eb-logo/MendelNewThistleLogo.png" alt="Encyclopedia Britannica" class="global-nav-center global-nav-logo non-homepage-logo" /> </a> <form method="get" action="/search" id="global-nav-search" class="md-search-form m-0 global-nav-search-bar-small global-nav-center search global-nav-center-search-container"> <div class="search-box position-relative col-100"> <label class="sr-only" for="global-nav-search-query">Search Britannica</label> <input name="query" id="global-nav-search-query" placeholder="Search Britannica..." class="form-control form-control-lg rounded-lg font-16 search-query pl-20 pr-70 shadow-sm" maxlength="200" autocomplete="off" aria-label="Search Britannica" /> <button class="search-reset-btn btn btn-link px-10 position-absolute top-0 h-100 d-none" type="reset"> <em class="material-icons" data-icon="close"></em> </button> <button class="search-submit btn btn-link text-blue px-10 position-absolute top-0 right-0 h-100" type="submit" disabled> <span class="sr-only">Click here to search</span> <em class="material-icons search-icon" data-icon="search"></em> </button> </div> </form> <div class="col-35 col-sm-auto text-right order-3 mr-lg-15 align-items-center d-flex justify-content-end"> <div class="d-none d-md-inline-block"> <SPAN class="marketing-HEADER_SUBSCRIPTION_DESKTOP2 marketing-content" data-marketing-id="HEADER_SUBSCRIPTION_DESKTOP2"><a href="https://subscription.britannica.com/subscribe?partnerCode=BP_Black_Friday_AUUS" class="subscribe-link btn btn-sm btn-outline-white-orange py-5 mr-10" target="_blank" rel="noopener"> Subscribe </a></SPAN></div> <div class="d-inline-block d-md-none mr-5 mr-sm-10"> <SPAN class="marketing-HEADER_SUBSCRIPTION_MOBILE marketing-content" data-marketing-id="HEADER_SUBSCRIPTION_MOBILE"><a href="https://subscription.britannica.com/subscribe?partnerCode=BP_Black_Friday_AUUS" class="subscribe-link btn btn-xs btn-orange-dark p-5" target="_blank" rel="noopener"> Subscribe </a></SPAN></div> <button class="js-toggle-user-dropdown js-toggle btn btn-sm btn-link link-white rounded-0 px-md-15 pl-5 pr-5"> <span class="d-none d-md-inline-block mr-5">Login</span> <em class="material-icons d-inline-block d-md-none font-16 font-sm-20" data-icon="account_circle"></em> <div class="d-none dropdown-menu-subscription-link">https://subscription.britannica.com/subscribe?partnerCode=BP_Black_Friday_AUUS</div> <em class="material-icons inactive-icon d-inline-block font-18" data-icon="keyboard_arrow_down"></em> <em class="material-icons active-icon d-inline-block font-18" data-icon="keyboard_arrow_up"></em> </button> </div> </div> </div> <div class="d-none hamburger-menu-subscription-link"><DIV class="marketing-HAMBURGER_MENU_CTA marketing-content" data-marketing-id="HAMBURGER_MENU_CTA"><a href="https://premium.britannica.com/premium-membership/?utm_source=premium&utm_medium=hamburger-menu&utm_campaign=black-friday-2024" class="subscribe-link btn btn-sm btn-orange py-5" target="_blank"> Subscribe <span class="d-none d-md-inline">&nbsp;Now</span> </a></DIV></div> <div id="global-nav-react"> <div class="d-none"> <ul> <li><a href="/">Home</a></li> <li><a href="/History-Society">History & Society</a></li> <li><a href="/Science-Tech">Science & Tech</a></li> <li><a href="/Biographies">Biographies</a></li> <li><a href="/Animals-Nature">Animals & Nature</a></li> <li><a href="/Geography-Travel">Geography & Travel</a></li> <li><a href="/Arts-Culture">Arts & Culture</a></li> <li><a href="/procon">ProCon</a></li> <li><a href="/money">Money</a></li> </ul> <ul> <li><a href="/quiz/browse">Games & Quizzes</a></li> <li><a href="/videos">Videos</a></li> <li><a href="/on-this-day">On This Day</a></li> <li><a href="/one-good-fact">One Good Fact</a></li> <li><a href="/dictionary">Dictionary</a></li> <li><a href="/new-articles">New Articles</a></li> </ul> <a href="/History-Society">History & Society</a> <ul> <li><a href="/browse/Lifestyles-Social-Issues">Lifestyles & Social Issues</a></li> <li><a href="/browse/Philosophy-Religion">Philosophy & Religion</a></li> <li><a href="/browse/Politics-Law-Government">Politics, Law & Government</a></li> <li><a href="/browse/World-History">World History</a></li> </ul> <a href="/Science-Tech">Science & Tech</a> <ul> <li><a href="/browse/Health-Medicine">Health & Medicine</a></li> <li><a href="/browse/Science">Science</a></li> <li><a href="/browse/Technology">Technology</a></li> </ul> <a href="/Biographies">Biographies</a> <ul> <li><a href="/browse/biographies">Browse Biographies</a></li> </ul> <a href="/Animals-Nature">Animals & Nature</a> <ul> <li><a href="/browse/Birds-Reptiles-Vertebrates">Birds, Reptiles & Other Vertebrates</a></li> <li><a href="/browse/Bugs-Mollusks-Invertebrates">Bugs, Mollusks & Other Invertebrates</a></li> <li><a href="/browse/Environment">Environment</a></li> <li><a href="/browse/Fossil-Geologic-Time">Fossils & Geologic Time</a></li> <li><a href="/browse/Mammals">Mammals</a></li> <li><a href="/browse/Plants">Plants</a></li> </ul> <a href="/Geography-Travel">Geography & Travel</a> <ul> <li><a href="/browse/Geography-Travel">Geography & Travel</a></li> </ul> <a href="/Arts-Culture">Arts & Culture</a> <ul> <li><a href="/browse/Entertainment-Pop-Culture">Entertainment & Pop Culture</a></li> <li><a href="/browse/Literature">Literature</a></li> <li><a href="/browse/Sports-Recreation">Sports & Recreation</a></li> <li><a href="/browse/Visual-Arts">Visual Arts</a></li> </ul> <ul> <li><a href="/stories/companion">Companions</a></li> <li><a href="/stories/demystified">Demystified</a></li> <li><a href="/gallery/browse">Image Galleries</a></li> <li><a href="/list/browse">Lists</a></li> <li><a href="/podcasts">Podcasts</a></li> <li><a href="/stories/spotlight">Spotlight</a></li> <li><a href="/summary">Summaries</a></li> <li><a href="/stories/the-forum">The Forum</a></li> <li><a href="/question">Top Questions</a></li> <li><a href="/stories/wtfact">#WTFact</a></li> </ul> <ul> <li><a href="https://kids.britannica.com/">Britannica Kids</a></li> </ul> </div> </div> </header> <div class="bg-navy-dark"> <div class="container-lg p-0 d-flex justify-content-center global-nav-categories-bar overflow-hidden"> <div class="slider js-slider position-relative d-inline-flex align-items-center mw-100 global-nav-slider category-snap-slider"> <div class="slider-container js-slider-container overflow-hidden d-flex font-14 overflow-hidden text-nowrap mx-5"> <a class="nav-bar-category mx-5 category-link-CHATBOT " href="/chatbot">Ask the Chatbot</a> <a class="nav-bar-category mx-5 category-link-QUIZZES " href="/quiz/browse">Games & Quizzes</a> <a class="nav-bar-category mx-5 category-link-HISTORY " href="/History-Society">History & Society</a> <a class="nav-bar-category mx-5 category-link-SCIENCE selected selected" href="/Science-Tech">Science & Tech</a> <a class="nav-bar-category mx-5 category-link-BIOS " href="/Biographies">Biographies</a> <a class="nav-bar-category mx-5 category-link-ANIMALS " href="/Animals-Nature">Animals & Nature</a> <a class="nav-bar-category mx-5 category-link-GEOGRAPHY " href="/Geography-Travel">Geography & Travel</a> <a class="nav-bar-category mx-5 category-link-ART " href="/Arts-Culture">Arts & Culture</a> <a class="nav-bar-category mx-5 category-link-PROCON " href="/procon">ProCon</a> <a class="nav-bar-category mx-5 category-link-MONEY " href="/money">Money</a> <a class="nav-bar-category mx-5 category-link-VIDEOS " href="/videos">Videos</a> </div> <button disabled class="prev-button js-prev-button position-absolute btn btn-circle shadow btn-blue " aria-label="Previous"> <span class="material-icons md-24" data-icon="keyboard_arrow_left"></span> </button> <button disabled class="next-button js-next-button position-absolute btn btn-circle shadow btn-blue " aria-label="Next"> <span class="material-icons md-24" data-icon="keyboard_arrow_right"></span> </button> </div> </div> </div> <main> <div class="md-page-wrapper"> <div id="content" class="md-content"> <script type="application/ld+json"> {"headline":"9 of the World’s Deadliest Spiders","image":{"url":"https://cdn.britannica.com/70/62770-131-C97CD1F7/Black-widow-spider.jpg","@type":"ImageObject"},"author":[{"name":"John P. Rafferty","url":"https://www.britannica.com/editor/John-P-Rafferty/6747","@type":"Person"}],"keywords":"9 of the World’s Deadliest Spiders","url":"https://www.britannica.com/list/9-of-the-worlds-deadliest-spiders","description":"This Encyclopedia Britannica list introduces 9 dangerous and deadly spiders.","publisher":{"name":"Encyclopedia Britannica","@type":"Organization","logo":{"url":"https://corporate.britannica.com/wp-content/themes/eb-corporate/_img/logo.png","@type":"ImageObject"}},"@context":"https://schema.org","@type":"article"} </script> <div class="list-content"> <div class="md-article-container list-container qa-content" data-feature-id="3793"> <div class="feature-container container-lg p-0 pb-40 p-md-20"> <aside class="d-none d-lg-block feature-left-rail p-20 pb-60 clear-catfish-ad"> <div class="feature-section"> <div class="label mb-15 font-serif">Discover</div> <div class="mobile-carousel-items"> <ul class="pl-0 lr-image-list font-14 m-0 mb-30 d-flex flex-md-column slider-container js-slider-container overflow-hidden discover"> <li class="mb-10 mr-10 mr-md-0 d-inline-flex"> <a href="/quiz/creepy-crawlies-quiz" class="d-block mr-10"> <img loading="lazy" src="https://cdn.britannica.com/98/173298-131-BC4550B3/wasp-Vespid-Wasp-Hymenoptera-antennas-eyes-wasps.jpg?w=68&h=68&s=crop" alt="wasp. Vespid Wasp (Vespidaea) with antennas and compound eyes drink nectar from a cherry. Hornets largest eusocial wasps, stinging insect in the order Hymenoptera, related to bees. Pollination" /> </a> <div class="link-container"> <a class="" href="/quiz/creepy-crawlies-quiz">Creepy Crawlies Quiz</a> </div> <div class="item-separator d-md-none"></div> </li> <li class="mb-10 mr-10 mr-md-0 d-inline-flex"> <a href="/quiz/animal-group-names" class="d-block mr-10"> <img loading="lazy" src="https://cdn.britannica.com/65/161265-131-DCC952FE/Sea-otter.jpg?w=68&h=68&s=crop" alt="Sea otter (Enhydra lutris), also called great sea otter, rare, completely marine otter of the northern Pacific, usually found in kelp beds. Floats on back. Looks like sea otter laughing. saltwater otters" /> </a> <div class="link-container"> <a class="" href="/quiz/animal-group-names">Animal Group Names</a> </div> <div class="item-separator d-md-none"></div> </li> <li class="mb-10 mr-10 mr-md-0 d-inline-flex"> <a href="/list/6-animals-that-eat-their-mates" class="d-block mr-10"> <img loading="lazy" src="https://cdn.britannica.com/37/235637-131-80A5D3FE/praying-mantis-walking-on-stone-ground-closeup.jpg?w=68&h=68&s=crop" alt="Close up of praying mantis walking on stone ground against a blurred background in Japan" /> </a> <div class="link-container"> <a class="" href="/list/6-animals-that-eat-their-mates">6 Animals That Eat Their Mates</a> </div> <div class="item-separator d-md-none"></div> </li> <li class="mb-10 mr-10 mr-md-0 d-inline-flex"> <a href="/quiz/name-that-thing-nature" class="d-block mr-10"> <img loading="lazy" src="https://cdn.britannica.com/68/237068-131-8D3EB18E/Name-that-Thing-Nature-composite-image.jpg?w=68&h=68&s=crop" alt="Name that Thing - Nature, composite image: carnation, dewclaw, fjords, lynx" /> </a> <div class="link-container"> <a class="" href="/quiz/name-that-thing-nature">Name That Thing: Nature</a> </div> <div class="item-separator d-md-none"></div> </li> <li class="mb-10 mr-10 mr-md-0 d-inline-flex"> <a href="/quiz/name-that-animal-volume-2" class="d-block mr-10"> <img loading="lazy" src="https://cdn.britannica.com/29/203929-131-4797839B/salamander-wild-Mexico-City-area.jpg?w=68&h=68&s=crop" alt="Axolotl salamander. Amphibian" /> </a> <div class="link-container"> <a class="" href="/quiz/name-that-animal-volume-2">Name That Animal! Volume 2</a> </div> <div class="item-separator d-md-none"></div> </li> <li class="mb-10 mr-10 mr-md-0 d-inline-flex"> <a href="/quiz/deadliest-animals-quiz" class="d-block mr-10"> <img loading="lazy" src="https://cdn.britannica.com/54/92754-131-661B61DB/lion-Panthera-leo.jpg?w=68&h=68&s=crop" alt="Lion (panthera leo)" /> </a> <div class="link-container"> <a class="" href="/quiz/deadliest-animals-quiz">Deadliest Animals Quiz</a> </div> <div class="item-separator d-md-none"></div> </li> <li class="mb-10 mr-10 mr-md-0 d-inline-flex"> <a href="/quiz/animal-factoids" class="d-block mr-10"> <img loading="lazy" src="https://cdn.britannica.com/07/167707-131-64BCF98F/Lammergeier.jpg?w=68&h=68&s=crop" alt="vulture. An adult bearded vulture at a raptor recovery center. The Gypaetus barbatus also known as the Lammergeier or Lammergeyer, is a bird of prey and considered an Old World vulture." /> </a> <div class="link-container"> <a class="" href="/quiz/animal-factoids">Animal Factoids</a> </div> <div class="item-separator d-md-none"></div> </li> <li class="mb-10 mr-10 mr-md-0 d-inline-flex"> <a href="/list/10-best-sports-rivalries-of-all-time" class="d-block mr-10"> <img loading="lazy" src="https://cdn.britannica.com/53/189653-131-A7E9422A/Kevin-Garnett-shooting-Ronny-Turiaf-Boston-Celtics-2008.jpg?w=68&h=68&s=crop" alt="NBA Lakers Celtics Finals Kevin Garnett shooting." /> </a> <div class="link-container"> <a class="" href="/list/10-best-sports-rivalries-of-all-time">10 Great Sports Rivalries</a> </div> <div class="item-separator d-md-none"></div> </li> <li class="mb-10 mr-10 mr-md-0 d-inline-flex"> <a href="/list/7-vestigial-features-of-the-human-body" class="d-block mr-10"> <img loading="lazy" src="https://cdn.britannica.com/80/176180-131-065C343F/Eye-Eyelash-Eyeball-Vision.jpg?w=68&h=68&s=crop" alt="Eye. Eyelash. Eyeball. Vision." /> </a> <div class="link-container"> <a class="" href="/list/7-vestigial-features-of-the-human-body">7 Vestigial Features of the Human Body</a> </div> <div class="item-separator d-md-none"></div> </li> <li class="mb-10 mr-10 mr-md-0 d-inline-flex"> <a href="/list/7-wonders-of-america" class="d-block mr-10"> <img loading="lazy" src="https://cdn.britannica.com/73/150373-131-DB2CFBDD/Teton-Range-Jackson-Lake-Wyoming-Grand-National.jpg?w=68&h=68&s=crop" alt="Jackson (Wyoming, United States). Jackson Lake (also called Jackson Hole), southern end of the Teton Range (the Grand Tetons), Grand Teton National Park, Wyoming, USA" /> </a> <div class="link-container"> <a class="" href="/list/7-wonders-of-america">7 Wonders of America</a> </div> <div class="item-separator d-md-none"></div> </li> <li class="mb-10 mr-10 mr-md-0 d-inline-flex"> <a href="/story/which-religion-is-the-oldest" class="d-block mr-10"> <img loading="lazy" src="https://cdn.britannica.com/91/223091-131-A986B08A/relief-Zoroastrian-god-Ahura-Mazda-Persepolis-Iran.jpg?w=68&h=68&s=crop" alt="Ahura Mazda - relief of the Zoroastrian god Ahura Mazda at the ancient ruins of Persepolis in Iran. Also known as Ormazd Zoroastrianism," /> </a> <div class="link-container"> <a class="" href="/story/which-religion-is-the-oldest">Which Religion Is the Oldest?</a> </div> <div class="item-separator d-md-none"></div> </li> <li class="mb-10 mr-10 mr-md-0 d-inline-flex"> <a href="/story/what-did-cleopatra-look-like" class="d-block mr-10"> <img loading="lazy" src="https://cdn.britannica.com/61/204161-131-F139DA5F/Cleopatra-temple-Horus-Egypt-Idfu.jpg?w=68&h=68&s=crop" alt="Cleopatra hieroglyphic carving the Ancient Egyptian queen Cleopatra. Wall of the Temple of Horus at Edfu, Egypt." /> </a> <div class="link-container"> <a class="" href="/story/what-did-cleopatra-look-like">What Did Cleopatra Look Like?</a> </div> <div class="item-separator d-md-none"></div> </li> <li class="mb-10 mr-10 mr-md-0 d-inline-flex"> <a href="/story/how-did-the-tradition-of-christmas-trees-start" class="d-block mr-10"> <img loading="lazy" src="https://cdn.britannica.com/79/202379-131-1EEF7D5C/Christmas-tree-holiday-pine.jpg?w=68&h=68&s=crop" alt="Christmas tree, holiday, pine" /> </a> <div class="link-container"> <a class="" href="/story/how-did-the-tradition-of-christmas-trees-start">How Did the Tradition of Christmas Trees Start? </a> </div> <div class="item-separator d-md-none"></div> </li> <li class="mb-10 mr-10 mr-md-0 d-inline-flex"> <a href="/story/why-cant-you-tickle-yourself" class="d-block mr-10"> <img loading="lazy" src="https://cdn.britannica.com/70/194970-131-9F41ECF1/Mother-daughter-garden.jpg?w=68&h=68&s=crop" alt="Mother tickling her daughter, sitting in a garden" /> </a> <div class="link-container"> <a class="" href="/story/why-cant-you-tickle-yourself">Why Can’t You Tickle Yourself?</a> </div> </li> </ul> </div> </div> </aside> <div class="reading-channel list-type-REGULAR"> <div class="grey-box w-100 grey-box-middle"> <div class="grey-box-content mx-auto w-100"> <script type="application/ld+json"> { "@context" : "https://schema.org", "@type" : "BreadcrumbList", "itemListElement" : [ { "@type" : "ListItem", "position" : 1, "item" : { "@id" : "https://www.britannica.com/list/browse", "name": "List" } } , { "@type" : "ListItem", "position" : 2, "item" : { "@id" : "https://www.britannica.com/list/browse/Science", "name": "Science" } } ] } </script> <nav class="breadcrumb mt-20 mb-30"> <span class="breadcrumb-item "> <a href="/" class="link-gray-600">Home</a> </span> <span class="breadcrumb-item "> <a class="link-gray-600" href="/list/browse">List</a> </span> <span class="breadcrumb-item "> <a class="link-gray-600" href="/list/browse/Science">Science</a> </span> </nav> <div class="mb-5"> <a class="SCIENCE font-weight-semi-bold super-category-badge rounded font-14" href="/Science-Tech"> Science & Tech </a> </div> <div> <div class="d-block d-md-none md-feature-tools float-right mb-15" style="right:20px" data-feature-id="3793"> <button class="js-tooltip-actions ml-10 btn btn-xs btn-outline-blue border shadow-sm pr-10" > <em class="material-icons md-icon ml-n10 my-n5 mr-5" data-icon="more_vert"></em> Actions </button> <div class="md-actions-popover popover popover-sm py-5 px-0 dropdown-menu"> <div> <button class="js-modal qa-cite-modal-button btn btn-sm btn-link gtm-topic-tool " data-modal="[data-feature-id=3793] .sm-cite-modal"> <em class="material-icons mr-5 ml-n10 my-n5 md-icon" data-icon="verified"></em> Cite </button> <div class="sm-cite-modal size-lg d-none"> <div class="md-modal-body"> <div class="h2 font-serif d-flex align-items-center pb-15 border-bottom mb-15"> <em class="material-icons text-blue mr-10">verified</em>Cite </div> <div class="font-serif"> While every effort has been made to follow citation style rules, there may be some discrepancies. Please refer to the appropriate style manual or other sources if you have any questions. </div> <div class="label mt-20 mb-10">Select Citation Style</div> <select class="js-citation-format-select form-select"> <option selected value="mla">MLA</option> <option value="apa">APA</option> <option value="chicago">Chicago Manual of Style</option> </select> <div class="citation font-serif border rounded p-15 mt-20" data-authors="John P. Rafferty" data-title="9 of the World’s Deadliest Spiders" data-published-date="7 Mar. 2014" data-url="https://www.britannica.com/list/9-of-the-worlds-deadliest-spiders" > <div class="citation-text"></div> </div> <button class="js-copy-citation-button mt-20 btn btn-xs btn-outline-blue border shadow-sm pr-10" > <em class="material-icons md-icon ml-n10 my-n5 mr-5" data-icon="file_copy"></em> <span class="js-citation-status-text">Copy Citation</span> </button> </div> </div> </div> <div> <button class="js-share-modal-button js-modal btn btn-sm btn-link gtm-topic-tool " data-modal="[data-feature-id=3793] .md-share-modal"> <em class="material-icons mr-5 ml-n10 my-n5 md-icon" data-icon="share"></em> Share </button> <div class="md-share-modal size-lg d-none qa-share-modal"> <div class="md-modal-body"> <div class="h2 font-serif d-flex align-items-center pb-15 border-bottom"> <em class="material-icons text-blue mr-10" data-icon="share"></em> Share </div> <div class="label my-20">Share to social media</div> <div class="md-social-toolbar-circle d-flex align-items-start inverted" data-value="share" title="9 of the World’s Deadliest Spiders" data-url="https://www.britannica.com/list/9-of-the-worlds-deadliest-spiders" > <a class="social-icon facebook justify-content-center d-flex align-items-center align-self-center" data-provider="facebook" href="https://www.facebook.com/BRITANNICA/" target="_blank" rel="noopener"><span>Facebook</span></a> <a class="social-icon x justify-content-center d-flex align-items-center align-self-center" data-provider="x" href="https://x.com/britannica" target="_blank" rel="noopener"><span>X</span></a> </div> <div class="label pt-20 mt-20 mb-5 border-top">URL</div> <a class="font-serif text-truncate d-inline-block" href="https://www.britannica.com/list/9-of-the-worlds-deadliest-spiders">https://www.britannica.com/list/9-of-the-worlds-deadliest-spiders</a> </div> </div> </div> </div> </div> <h1 class="content-title mb-5">9 of the World’s Deadliest Spiders</h1> <div class="d-none d-md-flex my-15"> <div class="mr-5"> <a href="javascript:window.print()" class=" btn btn-xs btn-outline-blue border shadow-sm pr-10" > <em class="material-icons md-icon ml-n10 my-n5 mr-5" data-icon="print"></em> Print </a> </div> <div class="mr-5"> <button class="js-modal qa-cite-modal-button gtm-topic-tool btn btn-xs btn-outline-blue border shadow-sm pr-10" data-modal="[data-feature-id=3793] .md-cite-modal"> <em class="material-icons md-icon ml-n10 my-n5 mr-5" data-icon="verified"></em> Cite </button> <div class="md-cite-modal size-lg d-none"> <div class="md-modal-body"> <div class="h2 font-serif d-flex align-items-center pb-15 border-bottom mb-15"> <em class="material-icons text-blue mr-10">verified</em>Cite </div> <div class="font-serif"> While every effort has been made to follow citation style rules, there may be some discrepancies. Please refer to the appropriate style manual or other sources if you have any questions. </div> <div class="label mt-20 mb-10">Select Citation Style</div> <select class="js-citation-format-select form-select"> <option selected value="mla">MLA</option> <option value="apa">APA</option> <option value="chicago">Chicago Manual of Style</option> </select> <div class="citation font-serif border rounded p-15 mt-20" data-authors="John P. Rafferty" data-title="9 of the World’s Deadliest Spiders" data-published-date="7 Mar. 2014" data-url="https://www.britannica.com/list/9-of-the-worlds-deadliest-spiders" > <div class="citation-text"></div> </div> <button class="js-copy-citation-button mt-20 btn btn-xs btn-outline-blue border shadow-sm pr-10" > <em class="material-icons md-icon ml-n10 my-n5 mr-5" data-icon="file_copy"></em> <span class="js-citation-status-text">Copy Citation</span> </button> </div> </div> </div> <div> <button class="js-share-modal-button js-modal gtm-topic-tool btn btn-xs btn-outline-blue border shadow-sm pr-10" data-modal=".md-share-modal"> <em class="material-icons md-icon ml-n10 my-n5 mr-5" data-icon="share"></em> Share </button> <div class="md-share-modal size-lg d-none qa-share-modal"> <div class="md-modal-body"> <div class="h2 font-serif d-flex align-items-center pb-15 border-bottom"> <em class="material-icons text-blue mr-10" data-icon="share"></em> Share </div> <div class="label my-20">Share to social media</div> <div class="md-social-toolbar-circle d-flex align-items-start inverted" data-value="share" title="9 of the World’s Deadliest Spiders" data-url="https://www.britannica.com/list/9-of-the-worlds-deadliest-spiders" > <a class="social-icon facebook justify-content-center d-flex align-items-center align-self-center" data-provider="facebook" href="https://www.facebook.com/BRITANNICA/" target="_blank" rel="noopener"><span>Facebook</span></a> <a class="social-icon x justify-content-center d-flex align-items-center align-self-center" data-provider="x" href="https://x.com/britannica" target="_blank" rel="noopener"><span>X</span></a> </div> <div class="label pt-20 mt-20 mb-5 border-top">URL</div> <a class="font-serif text-truncate d-inline-block" href="https://www.britannica.com/list/9-of-the-worlds-deadliest-spiders">https://www.britannica.com/list/9-of-the-worlds-deadliest-spiders</a> </div> </div> </div> </div> <div class="md-byline module-spacing font-14"> <div class="font-serif font-12"> <span class="written-by text-gray-700"> Written by </span> <div class="editor-popover popover p-0"> <a class="d-block p-20 gtm-byline font-12 byline-contributor" href="/editor/John-P-Rafferty/6747" > <div class="editor-title font-16 font-weight-bold">John P. Rafferty</div> <div class="editor-description font-12 font-serif mt-5 clamp-description text-black">John P. Rafferty writes about Earth processes and the environment. He serves currently as the editor of Earth and life sciences, covering climatology, geology, zoology, and other topics that relate to...</div> </a> <div data-popper-arrow></div> </div> <span class="btn btn-link editor-link p-0 qa-byline-link gtm-byline font-12 byline-contributor text-decoration-underline"> John P. Rafferty</span></div> <div class="font-serif font-12 text-gray-700"> <span class="qa-fact-checked-by">Fact-checked by</span> <div class="editor-popover popover p-0"> <a class="d-block p-20 font-12" href="/editor/The-Editors-of-Encyclopaedia-Britannica/4419" > <div class="editor-title font-16 font-weight-bold">The Editors of Encyclopaedia Britannica</div> <div class="editor-description font-12 font-serif mt-5 text-black">Encyclopaedia Britannica's editors oversee subject areas in which they have extensive knowledge, whether from years of experience gained by working on that content or via study for an advanced degree. They write new content and verify and edit content received from contributors.</div> </a> <div data-popper-arrow></div> </div> <span class="btn btn-link editor-link p-0 qa-byline-link font-12 "> The Editors of Encyclopaedia Britannica</span></div></div> </div> <article class="topic-content content"><div class="topic-paragraph font-serif md-list-intro pt-15 pb-20"><!--[BEFORE-INTRODUCTION]--><figure class="md-assembly md-feature-assembly print-false" data-type="1" data-descid="2"><div class="md-assembly-wrapper card-media " data-type="image"><a href="https://cdn.britannica.com/70/62770-131-C97CD1F7/Black-widow-spider.jpg" target="_blank" class="gtm-assembly-link position-relative d-flex align-items-center justify-content-center " data-href="*0"><img src="https://cdn.britannica.com/70/62770-131-C97CD1F7/Black-widow-spider.jpg?w=1000" alt="Black widow spider" data-width="900" data-height="675" loading="eager"><button class="magnifying-glass btn btn-circle position-absolute shadow btn-white top-10 right-10" aria-label="Zoom in"><em class="material-icons link-blue" data-icon="zoom_in"></em></button></a></div><figcaption class=""><div class="md-assembly-caption text-muted font-14 font-serif "><span></span></div><cite class="credit d-block mt-5">Encyclopædia Britannica, Inc.</cite></figcaption></figure><!--[BP]--><p class="topic-paragraph">More than 43,000 different species of <a href="https://www.britannica.com/animal/spider-arachnid" class="md-crosslink " data-show-preview="true">spiders </a>are found in the world. Of these, only a small number are said to be dangerous, and less than 30 (less than one-tenth of one percent) have been responsible for human deaths. Why are so few spiders harmful to humans? Much of the reason may result from the size differences between people and spiders. Spider <a href="https://www.britannica.com/science/venom" class="md-crosslink " data-show-preview="true">venom </a>is designed to work on smaller animals, but the venom of some species can produce skin lesions in people or produce allergic reactions that result in fatalities. It is important to understand, however, that “death by spider bite” is very rare since clinics, poison control centers, and hospitals often have various species-specific antivenin (the antitoxin) on hand to treat the bite. </p><!--[P]--><!--[MOD]--><span class="MOD"></span><!--[AFTER-INTRODUCTION]--></div><ul class="md-list-order-reverse md-mendel-list" style="counter-reset: item 10"><li><h2>Brown Recluse Spider (<em>Loxosceles reclusa</em>)</h2><div><figure class="md-assembly md-feature-assembly print-false" data-type="1" data-descid="1"><div class="md-assembly-wrapper card-media " data-type="image"><a href="https://cdn.britannica.com/26/6926-004-C38173DF/Brown-recluse-spider-cephalothorax.jpg" target="_blank" class="gtm-assembly-link position-relative d-flex align-items-center justify-content-center " data-href="*4641"><img src="https://cdn.britannica.com/26/6926-004-C38173DF/Brown-recluse-spider-cephalothorax.jpg?w=1000" alt="Brown recluse spider (Loxosceles reclusa) showing characteristic marking on head-thorax region" data-width="443" data-height="450" loading="eager"><button class="magnifying-glass btn btn-circle position-absolute shadow btn-white top-10 right-10" aria-label="Zoom in"><em class="material-icons link-blue" data-icon="zoom_in"></em></button></a></div><figcaption class=""><div class="md-assembly-caption text-muted font-14 font-serif "><span><a class="gtm-assembly-link md-assembly-title font-weight-bold d-inline font-sans-serif mr-5 media-overlay-link" target="_blank" href="https://cdn.britannica.com/26/6926-004-C38173DF/Brown-recluse-spider-cephalothorax.jpg" data-href="*4641">brown recluse spider</a><span>Brown recluse spider (<em>Loxosceles reclusa</em>) showing the characteristic violin-shaped marking on its cephalothorax.</span></span></div><cite class="credit d-block mt-5">John H. Gerard/Encyclopædia Britannica, Inc.</cite></figcaption></figure><!--[BP]--><p class="topic-paragraph">The <a href="https://www.britannica.com/animal/brown-recluse" class="md-crosslink " data-show-preview="true">brown recluse spider</a> is one of the most dangerous spiders in the United States. Its venom destroys the walls of blood vessels near the site of the bite, sometimes causing a large skin ulcer. Research in 2013 revealed that a protein in the spider’s venom targets phospholipid molecules, which make up a good portion of cell membranes, and transforms these molecules into simpler lipids. The wound that is produced may require several months to heal, or it may become infected, which could lead to the death of the victim. Deaths from brown recluse spider bites are rare.<br>Most brown recluse spiders, which are also called violin spiders, live in the western and southern United States. Most are about 7 mm (0.25 inch) and have a leg span of about 2.5 cm (1 inch). On the front half of its body (the cephalothorax), it has a dark violin-shaped design, the “neck” of which is formed by a conspicuous furrow on the midline of its back. The brown recluse has extended its range into parts of the northern United States, making its home in caves, rodent burrows, and other protected environments. Brown recluse spiders also set up shop in the undisturbed spaces of buildings, such as attics, storage areas, and wall or ceiling voids.</p><!--[P]--><!--[MOD]--><span class="MOD"></span></div><!--[LIST-ITEM-1]--><span class="LIST-ITEM-1"></span></li><li><h2>Brazilian Wandering Spiders (<em>Phoneutria fera</em> and <em>P. nigriventer</em>)</h2><div><figure class="md-assembly md-feature-assembly print-false" data-type="3" data-descid="7"><div class="md-assembly-wrapper card-media " data-type="video" video-id="256642"><a data-id="256642" class="gtm-assembly-link d-flex justify-content-center" style="--aspect-ratio: 16/9" href="/video/Do-we-really-swallow-spiders-in-our-sleep/-306330"><img src="https://cdn.britannica.com/42/256642-138-029D9042/Do-we-really-swallow-spiders-in-our-sleep.jpg?w=800&h=450&c=crop" alt="Do we really swallow spiders in our sleep? Debunking the myth that humans swallow eight spiders per year during sleep. In reality, humans swallow zero spiders in sleep. Misinformation, disinformation, spider, Snopes." loading="lazy"><script type="application/json"> { "sources": [ { "file" : "//content.jwplatform.com/manifests/wbPgLEpK.m3u8" } ], "image": "https://cdn.britannica.com/42/256642-138-029D9042/Do-we-really-swallow-spiders-in-our-sleep.jpg" ,"adfile": "//content.jwplatform.com/manifests/yQWggEXZ.m3u8" } </script><div class="btn btn-xl btn-white btn-circle position-absolute shadow" style="top: 50%; transform: translateY(-50%)"><em class="material-icons" data-icon="play_arrow"></em></div></a></div><figcaption class=""><div class="md-assembly-caption text-muted font-14 font-serif "><span><span class="md-assembly-title font-weight-bold mr-5 d-inline font-sans-serif md-video-caption" video-control="256642">Do we really swallow spiders in our sleep? </span><span>This myth is based on a web of lies.</span></span></div><cite class="credit d-block mt-5">Encyclopædia Britannica, Inc.</cite></figcaption></figure><!--[BP]--><p class="topic-paragraph"><a href="https://www.britannica.com/animal/wandering-spider" class="md-crosslink " data-show-preview="true">These species</a> are sometimes also referred to as banana spiders because they are frequently found on banana leaves. They have an aggressive defense posture, in which they raise their front legs straight up into the air. <em>Phoneutria</em> are poisonous to humans, and they are considered to be the deadliest of all the world’s spiders. Their venom is toxic to the nervous system, causing symptoms such as salivation, irregular heartbeat, and prolonged, painful erections (priapism) in men. Scientists are investigating the venom of <em>P. nigriventer</em> as a possible treatment for erectile dysfunction.<br>In late 2013, a family in London, England, had to move out of their home so it could be fumigated, because it became infested with tiny Brazilian wandering spiders. An egg sac deposited in a banana bunch was shipped to the family’s local grocery store. (The egg sac went undetected by the supermarket chain and the importing company it works with.) After the bananas were purchased, the egg sac broke open, releasing its potentially deadly contents.</p><!--[P]--><!--[MOD]--><span class="MOD"></span></div><!--[LIST-ITEM-2]--><span class="LIST-ITEM-2"></span></li><li><h2>Yellow sac spider (<em>Cheiracanthium inclusum</em>)</h2><div><!--[BP]--><p class="topic-paragraph">Yellow sac spiders are <a href="https://www.britannica.com/animal/sac-spider" class="md-crosslink " data-show-preview="true">Clubionids</a>, a family of spiders (order Araneida) that range in body length from 3 to 15 mm (about 0.12 to 0.6 inch) and build silken tubes under stones, in leaves, or in grass. <em>Cheiracanthium inclusum</em>, found throughout the United States, as well as in Mexico southward through South America, is venomous to humans and is often found indoors.<br>The spider’s venom is a cytotoxin (a substance that destroys a cell or impairs its function) that can produce necrotizing lesions, but such lesions occur rarely in bite victims. Still, redness and swelling at the site of the bite are common reactions. Yellow sac spiders are not docile creatures; a female yellow sac spider, for example may bite when defending her eggs.</p><!--[P]--><!--[MOD]--><span class="MOD"></span></div><!--[LIST-ITEM-3]--><span class="LIST-ITEM-3"></span></li><li><h2>Wolf spider (family Lycosidae)</h2><div><!--[BP]--><p class="topic-paragraph"><a href="https://www.britannica.com/animal/wolf-spider" class="md-crosslink " data-show-preview="true">Wolf spiders</a> belong to the family Lycosidae, a large and widespread group that is found throughout the world. They are named for their wolflike habit of chasing and pouncing upon prey. About 125 species occur in North America, whereas there are about 50 in Europe. Numerous species occur north of the Arctic Circle. Most are small to medium-sized. The largest has a body about 2.5 cm (1 inch) long and legs about the same length. Most wolf spiders are dark brown, and their hairy bodies are long and broad, with stout, long legs. They are noted for their running speed and commonly occur in grass or under stones, logs, or leaf litter, though they may invade human dwellings that harbor insects. Most species build silk-lined, tubular nests in the ground. Some conceal the entrance with rubbish, whereas others build a turretlike structure above it. A few species spin webs. Wolf spider eggs are contained in a gray silk sac attached to the female’s spinnerets, or silk-producing organs, so that she appears to be dragging a large ball. After hatching, the young spiders ride on the mother’s back for several days.<br>Although the spider is not considered to be aggressive, it will often bite people in self-defense. Wolf spiders are venomous, but their bites are not considered dangerous. (Some bite victims who are allergic to spider bites in general may become nauseous, dizzy, and develop an elevated heart rate, however.). The spider’s large fangs cause physical trauma at the site of the bite. The bite itself has been described as similar to that of a bee sting, and the venom the spider injects may cause itchiness at the site. This painful bite, coupled with their speed and startling appearance, can be unsettling, and some bite victims panic from the experience.</p><!--[P]--><!--[MOD]--><span class="MOD"></span></div><!--[LIST-ITEM-4]--><span class="LIST-ITEM-4"></span></li><li><h2>Black Widow Spider (<em>Latrodectus mactans</em>)</h2><div><figure class="md-assembly md-feature-assembly print-false" data-type="1" data-descid="2"><div class="md-assembly-wrapper card-media " data-type="image"><a href="https://cdn.britannica.com/51/193551-050-F1B9329D/Black-widow-spider.jpg" target="_blank" class="gtm-assembly-link position-relative d-flex align-items-center justify-content-center " data-href="*222084"><img src="https://cdn.britannica.com/51/193551-050-F1B9329D/Black-widow-spider.jpg?w=1000" alt="black widow spider (Latrodectus mactans), arachnids" data-width="1600" data-height="1067" loading="eager"><button class="magnifying-glass btn btn-circle position-absolute shadow btn-white top-10 right-10" aria-label="Zoom in"><em class="material-icons link-blue" data-icon="zoom_in"></em></button></a></div><figcaption class=""><div class="md-assembly-caption text-muted font-14 font-serif "><span><a class="gtm-assembly-link md-assembly-title font-weight-bold d-inline font-sans-serif mr-5 media-overlay-link" target="_blank" href="https://cdn.britannica.com/51/193551-050-F1B9329D/Black-widow-spider.jpg" data-href="*222084">black widow spider (<em>Latrodectus mactans</em>)</a></span></div><cite class="credit d-block mt-5">Encyclopædia Britannica, Inc./Patrick O'Neill Riley</cite></figcaption></figure><!--[BP]--><p class="topic-paragraph">The <a href="https://www.britannica.com/animal/black-widow-spider" class="md-crosslink " data-show-preview="true">black widow</a> is responsible for more than 2,500 visits to poison control centers every year in the U.S. It is one species that can be found from the United States and parts of Canada through Latin America and the West Indies. The most common member of <em>Latrodectus</em> in North America, it makes its home in a variety of settings, such as woodpiles, burrows, or among plants that serve as supports for its web.<br>The female is shiny black and usually has a reddish to yellow hourglass design on the underside of the spherical abdomen. Sometimes two small triangles, instead of a complete hourglass, are present. The body is about 2.5 cm (1 inch) long. The male, seldom seen because it is often killed and eaten by the female after mating (hence the spider’s name), is about one-fourth the size of the female. In addition to the hourglass design, the male often has pairs of red and white stripes on the sides of the abdomen.<br>Its bite, which may feel like a pinprick on the skin, often produces severe muscle pain and cramping, nausea, and mild paralysis of the diaphragm, which makes breathing difficult. Most victims recover without serious complications. Although the bite is thought to be fatal to very small children and the elderly, no deaths have been attributed to bites by widow spiders in the United States.</p><!--[P]--><!--[MOD]--><span class="MOD"></span></div><!--[LIST-ITEM-5]--><span class="LIST-ITEM-5"></span></li><li><h2>Brown Widow Spider (<em>Latrodectus geometricus</em>)</h2><div><figure class="md-assembly md-feature-assembly print-false" data-type="1" data-descid="2"><div class="md-assembly-wrapper card-media " data-type="image"><a href="https://cdn.britannica.com/50/193550-050-26AE18FE/Brown-widow-spider.jpg" target="_blank" class="gtm-assembly-link position-relative d-flex align-items-center justify-content-center " data-href="*226137"><img src="https://cdn.britannica.com/50/193550-050-26AE18FE/Brown-widow-spider.jpg?w=1000" alt="brown widow spider (Latrodectus geometricus), arachnids" data-width="1600" data-height="1068" loading="eager"><button class="magnifying-glass btn btn-circle position-absolute shadow btn-white top-10 right-10" aria-label="Zoom in"><em class="material-icons link-blue" data-icon="zoom_in"></em></button></a></div><figcaption class=""><div class="md-assembly-caption text-muted font-14 font-serif "><span><a class="gtm-assembly-link md-assembly-title font-weight-bold d-inline font-sans-serif mr-5 media-overlay-link" target="_blank" href="https://cdn.britannica.com/50/193550-050-26AE18FE/Brown-widow-spider.jpg" data-href="*226137">Brown widow spider</a></span></div><cite class="credit d-block mt-5">Encyclopædia Britannica, Inc./Patrick O'Neill Riley</cite></figcaption></figure><!--[BP]--><p class="topic-paragraph">The brown widow is thought to have evolved in Africa, but the first specimen described came from South America. It is classified as an invasive species elsewhere around the world. Brown widow populations have appeared in southern California, the Caribbean, the U.S. states of the Gulf Coast, as well as in Japan, South Africa and Madagascar, Australia, and Cyprus. The species makes its home in buildings, inside old tires, and under automobiles, as well as among shrubs and other vegetation.<br>The spider has a brownish appearance that ranges from tan to almost black. The abdomens of some specimens have ornate dark-brown, black, white, yellow, or orange markings. Unlike other members of the genus, the hourglass marking on the underside of the brown widow is orange.<br>Brown widow venom is considered to be twice as powerful as that of the black widow; however, the species is not aggressive and only injects a tiny amount of venom when it bites. Still, brown widow bites were associated with the deaths of two people in Madagascar in the early 1990s. (These victims were in poor health and were not treated with antivenin.)</p><!--[P]--><!--[MOD]--><span class="MOD"></span></div><!--[LIST-ITEM-6]--><span class="LIST-ITEM-6"></span></li><li><h2>Red Widow Spider (<em>Latrodectus bishopi</em>)</h2><div><figure class="md-assembly md-feature-assembly print-false" data-type="1" data-descid="2"><div class="md-assembly-wrapper card-media " data-type="image"><a href="https://cdn.britannica.com/49/193549-050-FD83BFFA/red-widow-spider.jpg" target="_blank" class="gtm-assembly-link position-relative d-flex align-items-center justify-content-center " data-href="*222082"><img src="https://cdn.britannica.com/49/193549-050-FD83BFFA/red-widow-spider.jpg?w=1000" alt="red widow spider (Latrodectus bishopi), arachnids" data-width="1600" data-height="1068" loading="eager"><button class="magnifying-glass btn btn-circle position-absolute shadow btn-white top-10 right-10" aria-label="Zoom in"><em class="material-icons link-blue" data-icon="zoom_in"></em></button></a></div><figcaption class=""><div class="md-assembly-caption text-muted font-14 font-serif "><span><a class="gtm-assembly-link md-assembly-title font-weight-bold d-inline font-sans-serif mr-5 media-overlay-link" target="_blank" href="https://cdn.britannica.com/49/193549-050-FD83BFFA/red-widow-spider.jpg" data-href="*222082">red widow spider</a><span>A red widow spider (<em>Latrodectus bishopi</em>) is found in sandy areas of Florida.</span></span></div><cite class="credit d-block mt-5">Encyclopædia Britannica, Inc./Patrick O'Neill Riley</cite></figcaption></figure><!--[BP]--><p class="topic-paragraph">The third widow spider on this list is the red widow, or red-legged widow. The spider’s appearance is distinguished from other widow spiders by its reddish cephalothorax and legs and its reddish-brown to black colored abdomen. Many red widows have a red mark on the underside of the abdomen, which may be either hourglass-shaped, triangle-shaped, or indistinct. The top of the abdomen is spotted red or orange, with each spot surrounded by a yellow or white outline. The legspan of an adult female is 1.5-2 inches, whereas the male is only about one-third of that size.<br>Currently, red widow spiders inhabit palmetto-dominated scrublands in central and southern Florida; however, some experts believe that this range may be expanding. The spider feeds on insects, and it is not considered to be aggressive toward people. However, it has been known to bite when it is protecting its eggs or when it is trapped against a person’s skin by clothes or footwear. The bite of the red widow is similar to that of the black widow, and identical symptoms (pain, cramping, nausea, etc.) typically result. Likewise, death from a red widow bite is rare, since the spider injects such a small amount of venom. Very young children, the elderly, and people with health problems are most vulnerable to red widow spider bites.</p><!--[P]--><!--[MOD]--><span class="MOD"></span></div><!--[LIST-ITEM-7]--><span class="LIST-ITEM-7"></span></li><li><h2>Redback Spider (<em>Latrodectus hasselti</em>)</h2><div><figure class="md-assembly md-feature-assembly print-false" data-type="1" data-descid="2"><div class="md-assembly-wrapper card-media " data-type="image"><a href="https://cdn.britannica.com/48/193548-050-4C742966/Redback-spider.jpg" target="_blank" class="gtm-assembly-link position-relative d-flex align-items-center justify-content-center " data-href="*221184"><img src="https://cdn.britannica.com/48/193548-050-4C742966/Redback-spider.jpg?w=1000" alt="redback spider (Latrodectus hasselti), arachnids" data-width="1600" data-height="1068" loading="eager"><button class="magnifying-glass btn btn-circle position-absolute shadow btn-white top-10 right-10" aria-label="Zoom in"><em class="material-icons link-blue" data-icon="zoom_in"></em></button></a></div><figcaption class=""><div class="md-assembly-caption text-muted font-14 font-serif "><span><a class="gtm-assembly-link md-assembly-title font-weight-bold d-inline font-sans-serif mr-5 media-overlay-link" target="_blank" href="https://cdn.britannica.com/48/193548-050-4C742966/Redback-spider.jpg" data-href="*221184">Redback spider (<em>Latrodectus hasselti</em>)</a></span></div><cite class="credit d-block mt-5">Encyclopædia Britannica, Inc./Patrick O'Neill Riley</cite></figcaption></figure><!--[BP]--><p class="topic-paragraph">The <a href="https://www.britannica.com/animal/redback" class="md-crosslink " data-show-preview="true">redback </a>is another cousin of the black widow <em>L. mactans</em>; however, this species is not as widespread. It is native to Australia, but it has spread to New Zealand, Belgium, and Japan through grape exports. (The spider often builds nests and webs on grape leaves and inside bunches.) The species is widespread throughout Australia, living in all of the continent’s varied environments, except for its hottest deserts and frigid mountaintops. The species is also found in urban areas, frequently making nests in human dwellings. The redback is identified by its prominent red stripe or hourglass-shaped mark on its black-colored back. This mark is more noticeable on female redbacks than on males.<br>Redback spiders are not aggressive and are more likely to play dead when disturbed, but a female spider defending her eggs is very likely to bite. Bites also occur when the spider climbs into shoes or clothing and becomes trapped against the victim’s skin when he or she is dressing. Both male and female redbacks are venomous, but most envenomations primarily result from female bites. Only 10-20% of all victims bitten are envenomed. The venom is a mix neurotoxins called alpha-latrotoxins, which produces pain, sweating, rapid heartbeats, and swollen lymph nodes. The spider can moderate the amount of venom it injects, and the severity of these symptoms often depend on how much venom is delivered. More than 250 redback bites are treated each year in Australia, many with antivenin. Researchers and physicians are split on the effectiveness of redback antivenin, with some studies indicating that it was not effective in treating symptoms or relieving pain. Nevertheless, the last human death attributed to redback envenomation occurred in 1956.</p><!--[P]--><!--[MOD]--><span class="MOD"></span></div><!--[LIST-ITEM-8]--><span class="LIST-ITEM-8"></span></li><li><h2>Funnel-web Spiders (family Dipluridae)</h2><div><figure class="md-assembly md-feature-assembly print-false" data-type="1" data-descid="2"><div class="md-assembly-wrapper card-media " data-type="image"><a href="https://cdn.britannica.com/46/193546-050-7865670F/Sydney-funnel-web-spider.jpg" target="_blank" class="gtm-assembly-link position-relative d-flex align-items-center justify-content-center " data-href="*221183"><img src="https://cdn.britannica.com/46/193546-050-7865670F/Sydney-funnel-web-spider.jpg?w=1000" alt="Sydney funnel-web spider (Atrax robustus), arachnids" data-width="1600" data-height="1067" loading="eager"><button class="magnifying-glass btn btn-circle position-absolute shadow btn-white top-10 right-10" aria-label="Zoom in"><em class="material-icons link-blue" data-icon="zoom_in"></em></button></a></div><figcaption class=""><div class="md-assembly-caption text-muted font-14 font-serif "><span><a class="gtm-assembly-link md-assembly-title font-weight-bold d-inline font-sans-serif mr-5 media-overlay-link" target="_blank" href="https://cdn.britannica.com/46/193546-050-7865670F/Sydney-funnel-web-spider.jpg" data-href="*221183">Sydney funnel-web spider (<em>Atrax robustus</em>) </a><span>Sydney funnel-web spider (<em>Atrax robustus</em>).</span></span></div><cite class="credit d-block mt-5">Encyclopædia Britannica, Inc./Patrick O'Neill Riley</cite></figcaption></figure><!--[BP]--><p class="topic-paragraph"><a href="https://www.britannica.com/animal/funnel-web-spider" class="md-crosslink " data-show-preview="true">This family of spiders</a> in the order Araneida are named for their funnel-shaped webs, which open wide at the mouth of the tube. The spider sits in the narrow funnel waiting for prey to contact the web. When this happens, the spider rushes out and captures the insect prey at the funnel’s mouth. The most important genera are <em>Evagrus</em>, <em>Brachythele</em>, and <em>Microhexura</em> in North America, <em>Trechona</em> in South America, and the poisonous members of the <em>Atrax</em> genus in Australia.<br>The species <em>Atrax robustus</em> and <em>A. formidabilis</em> are large, brown bulky spiders that are much feared in southern and eastern Australia because of their venomous bites. Several human deaths from the bites of these aggressive spiders have been recorded in the Sydney area since the 1920s. An antidote to the main toxin in their venom has been developed which is effective if administered to victims soon after they have been bitten.</p><!--[P]--><!--[MOD]--><span class="MOD"></span></div><!--[LIST-ITEM-9]--><span class="LIST-ITEM-9"></span></li></ul><span class="AM-END-OF-ARTICLE am-inline"></span></article> </div> </div> </div> <aside class="cm-rightrail d-none d-md-block ad-rail"></aside> </div> </div> </div> <div class="grid gx-0"> <div class="col"> <div class="md-loading hidden display-4 font-weight-normal"></div> <div class="text-center my-20 mb-100"> <button class="md-infinite-load-next btn btn-blue" data-value="next-page">Load More</button> </div> </div> <div class="col-md-da-320 hidden-xs"> </div> </div></div> </div> </main> <div id="md-footer"></div> <noscript><iframe src="//www.googletagmanager.com/ns.html?id=GTM-5W6NC8" height="0" width="0" style="display:none;visibility:hidden"></iframe></noscript> <script type="text/javascript" id="_informizely_script_tag"> var IzWidget = IzWidget || {}; (function (d) { var scriptElement = d.createElement('script'); scriptElement.type = 'text/javascript'; scriptElement.async = true; scriptElement.src = "https://insitez.blob.core.windows.net/site/f780f33e-a610-4ac2-af81-3eb184037547.js"; var node = d.getElementById('_informizely_script_tag'); node.parentNode.insertBefore(scriptElement, node); } )(document); </script> <!-- Ortto ebmwprod capture code --> <script> window.ap3c = window.ap3c || {}; var ap3c = window.ap3c; ap3c.cmd = ap3c.cmd || []; ap3c.cmd.push(function() { ap3c.init('ZO4siT4cLwnykPnzZWJtd3Byb2Q', 'https://engage.email.britannica.com/'); ap3c.track({v: 0}); }); ap3c.activity = function(act) { ap3c.act = (ap3c.act || []); ap3c.act.push(act); }; var s, t; s = document.createElement('script'); s.type = 'text/javascript'; s.src = "https://engage.email.britannica.com/app.js"; t = document.getElementsByTagName('script')[0]; t.parentNode.insertBefore(s, t); </script> <script class="marketing-page-info" type="application/json"> {"pageType":"List","templateName":null,"pageNumber":1,"pagesTotal":10,"pageId":3793,"pageLength":null,"initialLoad":true,"lastPageOfScroll":false} </script> <script class="marketing-content-info" type="application/json"> [] </script> <script src="https://cdn.britannica.com/mendel-resources/3-130/js/libs/jquery-3.5.0.min.js?v=3.130.14"></script> <script type="text/javascript" data-type="Init Mendel Code Splitting"> (function() { $.ajax({ dataType: 'script', cache: true, url: 'https://cdn.britannica.com/mendel-resources/3-130/dist/list-page.js?v=3.130.14' }); })(); </script> <script class="analytics-metadata" type="application/json"> {"leg":"B","adLeg":"B","userType":"ANONYMOUS","pageType":"List","pageSubtype":null,"articleTemplateType":null,"gisted":false,"pageNumber":1,"hasSummarizeButton":false,"hasAskButton":false} </script> <script type="text/javascript"> EBStat={accountId:-1,hostnameOverride:'webstats.eb.com',domain:'www.britannica.com', json:''}; </script> <script type="text/javascript"> ( function() { $.ajax( { dataType: 'script', cache: true, url: '//www.britannica.com/webstats/mendelstats.js?v=1' } ) .done( function() { try {writeStat(null,EBStat);} catch(err){} } ); })(); </script> <div id="bc-fixed-dialogue"></div> </body> </html>

Pages: 1 2 3 4 5 6 7 8 9 10