{"id":2343,"date":"2019-09-04T11:00:05","date_gmt":"2019-09-04T15:00:05","guid":{"rendered":"https:\/\/www.headlice.org\/comb\/?page_id=2343"},"modified":"2024-09-03T18:59:15","modified_gmt":"2024-09-03T22:59:15","slug":"lousology-101","status":"publish","type":"page","link":"https:\/\/www.headlice.org\/comb\/what-are-head-lice-and-nits\/frequently-asked-questions\/lousology-101\/","title":{"rendered":"Lousology 101"},"content":{"rendered":"\n<h2 class=\"wp-block-heading\">Images &amp; Biology of Head Lice<\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Nits (the eggs of the head louse) are small yellowish-white, oval-shaped eggs that are &#8220;to the side of a hair shaft glued&#8221; at an angle.<\/li>\n\n\n\n<li>Nits must be laid by live lice. <\/li>\n\n\n\n<li>You cannot &#8220;catch nits.&#8221;<\/li>\n\n\n\n<li>Once laid, it takes 7-10 days for a nit to hatch, and another 7-10 days for the female to mature and begin laying her own eggs.<\/li>\n\n\n\n<li>Head lice are clear in color when hatched, then quickly develop a reddish-brown color after feeding.<\/li>\n\n\n\n<li>Head lice are about the size of sesame seeds.<\/li>\n\n\n\n<li>Head lice have six legs equipped with claws to grasp the hair.<\/li>\n\n\n\n<li>Head lice are crawling insects. They cannot hop, jump, or fly.<\/li>\n\n\n\n<li>Head lice do not thrive on pets.<\/li>\n\n\n\n<li>Head lice are small, wingless insects which feed on human blood. They need human blood in order to survive.<\/li>\n\n\n\n<li>Head lice live for approximately 30 days on a host and a female louse may lay up to 100 nits (eggs).<\/li>\n\n\n\n<li>Head lice off of their human hosts will starve. The NPA suggests that, in most cases, a head louse will not survive for more than 24 hours off of its human host.<\/li>\n<\/ul>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter\"><img loading=\"lazy\" decoding=\"async\" width=\"302\" height=\"305\" src=\"https:\/\/www.headlice.org\/comb\/wp-content\/uploads\/2019\/09\/lifecycle1.gif\" alt=\"\" class=\"wp-image-2367\"\/><\/figure><\/div>\n\n\n<h4 class=\"wp-block-heading\">Images below appear courtesy of Rick Speare<\/h4>\n\n\n\n<figure class=\"wp-block-gallery has-nested-images columns-default is-cropped wp-block-gallery-1 is-layout-flex wp-block-gallery-is-layout-flex\">\n<figure class=\"wp-block-image\"><img loading=\"lazy\" decoding=\"async\" width=\"325\" height=\"207\" data-id=\"2346\" src=\"https:\/\/www.headlice.org\/comb\/wp-content\/uploads\/2019\/09\/electron_louse.gif\" alt=\"\" class=\"wp-image-2346\"\/><figcaption class=\"wp-element-caption\">Human Head Louse<\/figcaption><\/figure>\n\n\n\n<figure class=\"wp-block-image\"><img loading=\"lazy\" decoding=\"async\" width=\"335\" height=\"207\" data-id=\"2347\" src=\"https:\/\/www.headlice.org\/comb\/wp-content\/uploads\/2019\/09\/electron_nit.gif\" alt=\"\" class=\"wp-image-2347\"\/><figcaption class=\"wp-element-caption\">Nit attached to Hair Shaft<\/figcaption><\/figure>\n<\/figure>\n\n\n\n<h4 class=\"wp-block-heading\">Images below appear courtesy of William B. Swain<\/h4>\n\n\n\n<figure class=\"wp-block-gallery has-nested-images columns-default is-cropped wp-block-gallery-2 is-layout-flex wp-block-gallery-is-layout-flex\">\n<figure class=\"wp-block-image\"><img loading=\"lazy\" decoding=\"async\" width=\"325\" height=\"247\" data-id=\"2353\" src=\"https:\/\/www.headlice.org\/comb\/wp-content\/uploads\/2019\/09\/swain01.jpg\" alt=\"\" class=\"wp-image-2353\" srcset=\"https:\/\/www.headlice.org\/comb\/wp-content\/uploads\/2019\/09\/swain01.jpg 325w, https:\/\/www.headlice.org\/comb\/wp-content\/uploads\/2019\/09\/swain01-300x228.jpg 300w\" sizes=\"auto, (max-width: 325px) 100vw, 325px\" \/><figcaption class=\"wp-element-caption\">Louse Removed from Human Scalp<\/figcaption><\/figure>\n\n\n\n<figure class=\"wp-block-image\"><img loading=\"lazy\" decoding=\"async\" width=\"325\" height=\"212\" data-id=\"2354\" src=\"https:\/\/www.headlice.org\/comb\/wp-content\/uploads\/2019\/09\/swain02.jpg\" alt=\"\" class=\"wp-image-2354\" srcset=\"https:\/\/www.headlice.org\/comb\/wp-content\/uploads\/2019\/09\/swain02.jpg 325w, https:\/\/www.headlice.org\/comb\/wp-content\/uploads\/2019\/09\/swain02-300x196.jpg 300w\" sizes=\"auto, (max-width: 325px) 100vw, 325px\" \/><figcaption class=\"wp-element-caption\">Lice Nit on Human Hair<\/figcaption><\/figure>\n\n\n\n<figure class=\"wp-block-image\"><img loading=\"lazy\" decoding=\"async\" width=\"325\" height=\"243\" data-id=\"2355\" src=\"https:\/\/www.headlice.org\/comb\/wp-content\/uploads\/2019\/09\/swain03.jpg\" alt=\"\" class=\"wp-image-2355\" srcset=\"https:\/\/www.headlice.org\/comb\/wp-content\/uploads\/2019\/09\/swain03.jpg 325w, https:\/\/www.headlice.org\/comb\/wp-content\/uploads\/2019\/09\/swain03-300x224.jpg 300w, https:\/\/www.headlice.org\/comb\/wp-content\/uploads\/2019\/09\/swain03-260x195.jpg 260w\" sizes=\"auto, (max-width: 325px) 100vw, 325px\" \/><figcaption class=\"wp-element-caption\">Head Lice Removed from Human Head<\/figcaption><\/figure>\n<\/figure>\n\n\n\n<h4 class=\"wp-block-heading\">Images below appear courtesy of Dr. Gaetano Scanni<\/h4>\n\n\n\n<figure class=\"wp-block-gallery has-nested-images columns-default is-cropped wp-block-gallery-3 is-layout-flex wp-block-gallery-is-layout-flex\">\n<figure class=\"wp-block-image\"><img loading=\"lazy\" decoding=\"async\" width=\"473\" height=\"291\" data-id=\"2349\" src=\"https:\/\/www.headlice.org\/comb\/wp-content\/uploads\/2019\/09\/scanni1.jpg\" alt=\"\" class=\"wp-image-2349\" srcset=\"https:\/\/www.headlice.org\/comb\/wp-content\/uploads\/2019\/09\/scanni1.jpg 473w, https:\/\/www.headlice.org\/comb\/wp-content\/uploads\/2019\/09\/scanni1-300x185.jpg 300w\" sizes=\"auto, (max-width: 473px) 100vw, 473px\" \/><figcaption class=\"wp-element-caption\">Lice with clustered feces.<\/figcaption><\/figure>\n\n\n\n<figure class=\"wp-block-image\"><img loading=\"lazy\" decoding=\"async\" width=\"475\" height=\"292\" data-id=\"2350\" src=\"https:\/\/www.headlice.org\/comb\/wp-content\/uploads\/2019\/09\/scanni2.jpg\" alt=\"\" class=\"wp-image-2350\" srcset=\"https:\/\/www.headlice.org\/comb\/wp-content\/uploads\/2019\/09\/scanni2.jpg 475w, https:\/\/www.headlice.org\/comb\/wp-content\/uploads\/2019\/09\/scanni2-300x184.jpg 300w\" sizes=\"auto, (max-width: 475px) 100vw, 475px\" \/><figcaption class=\"wp-element-caption\">Pediculus feces.<\/figcaption><\/figure>\n\n\n\n<figure class=\"wp-block-image\"><img loading=\"lazy\" decoding=\"async\" width=\"478\" height=\"246\" data-id=\"2351\" src=\"https:\/\/www.headlice.org\/comb\/wp-content\/uploads\/2019\/09\/scanni3.jpg\" alt=\"\" class=\"wp-image-2351\" srcset=\"https:\/\/www.headlice.org\/comb\/wp-content\/uploads\/2019\/09\/scanni3.jpg 478w, https:\/\/www.headlice.org\/comb\/wp-content\/uploads\/2019\/09\/scanni3-300x154.jpg 300w\" sizes=\"auto, (max-width: 478px) 100vw, 478px\" \/><figcaption class=\"wp-element-caption\">Lice feces on head.<\/figcaption><\/figure>\n<\/figure>\n\n\n\n<h2 class=\"wp-block-heading\">Head Lice of Different Sizes<\/h2>\n\n\n\n<div style=\"overflow-x:auto;\">\n\n<table cellpadding=\"0\" cellspacing=\"3\" bordercolor=\"#111111\" width=\"99%\">\n  <tbody><tr>\n    <td width=\"100%\" colspan=\"4\">\n    <font face=\"Arial\" style=\"font-size: 9pt\">\n    <a target=\"_blank\" href=\"\/images\/npalice.jpg\" rel=\"noopener noreferrer\">\n    <img loading=\"lazy\" decoding=\"async\" src=\"\/images\/tn_npalice.jpg\" width=\"96\" height=\"55\"><\/a><a href=\"\/images\/adlice.gif\"><br>\n      Lice of different sizes<\/a><\/font><br>\n&nbsp;<\/td>\n  <\/tr>\n \n  <tr>\n    <td>\n    <font face=\"Arial\" style=\"font-size: 9pt\"><a href=\"\/images\/lousepic.jpg\" target=\"_blank\" rel=\"noopener noreferrer\">\n    <img loading=\"lazy\" decoding=\"async\" src=\"\/images\/tn_lousepic.jpg\" width=\"96\" height=\"68\"><\/a><a href=\"\/images\/lousepic.jpg\"><br>\n      Head louse<\/a><\/font><\/td>\n    <td>\n    <font face=\"Arial\" style=\"font-size: 9pt\"><a href=\"\/images\/adlice.gif\" target=\"_blank\" rel=\"noopener noreferrer\">\n    <img loading=\"lazy\" decoding=\"async\" src=\"\/images\/tn_adlice.jpg\" width=\"96\" height=\"63\"><\/a><a href=\"\/images\/adlice.gif\"><br>\n      Adult female &amp; adult male<\/a><\/font><\/td>\n    <td>\n    <font face=\"Arial\" style=\"font-size: 9pt\"><a href=\"\/images\/louses.jpg\" target=\"_blank\" rel=\"noopener noreferrer\">\n    <img loading=\"lazy\" decoding=\"async\" src=\"\/images\/tn_louses.jpg\" width=\"96\" height=\"69\"><\/a><a href=\"\/images\/louses.jpg\"><br>\n      Nymph (newborn louse)<\/a><br>\n    <a href=\"\/images\/louses.jpg\">&amp; adult louse<\/a><\/font><\/td>\n    <td>\n    <font face=\"Arial\" style=\"font-size: 9pt\"><a href=\"\/images\/liceclaw.gif\" target=\"_blank\" rel=\"noopener noreferrer\">\n    <img loading=\"lazy\" decoding=\"async\" src=\"\/images\/tn_liceclaw.jpg\" width=\"70\" height=\"72\"><\/a><a href=\"\/images\/liceclaw.gif\"><br>\n      Tarsal claw of the head louse<\/a><\/font><\/td>\n  <\/tr>\n  <tr>\n    <td>\n    <br>\n    <font face=\"Arial\" style=\"font-size: 9pt\"><a href=\"\/images\/nitsimage.jpg\" target=\"_blank\" rel=\"noopener noreferrer\">\n    <img loading=\"lazy\" decoding=\"async\" src=\"\/images\/tn_nitsimage.jpg\" width=\"60\" height=\"72\"><\/a><a href=\"\/images\/nitsimage.jpg\"><br>\n      Nits compared in size to<\/a><br>\n    <a href=\"\/images\/nitsimage.jpg\">the head of a pin<\/a><\/font><\/td>\n    <td>\n    <font face=\"Arial\" style=\"font-size: 9pt\"><a href=\"\/images\/nitpic.jpg\" target=\"_blank\" rel=\"noopener noreferrer\">\n    <img loading=\"lazy\" decoding=\"async\" src=\"\/images\/tn_nitpic.jpg\" width=\"93\" height=\"72\"><\/a><a href=\"\/images\/nitpic.jpg\"><br>\n      Louse egg (nit)<\/a><\/font><\/td>\n    <td>\n    <font face=\"Arial\" style=\"font-size: 9pt\"><!--a href=\"\/images\/hatchpic.jpg\" target=\"_blank\" rel=\"noopener noreferrer\">\n    <img loading=\"lazy\" decoding=\"async\" src=\"\/images\/tn_hatchpic.jpg\" width=\"96\" height=\"72\"><\/a><a href=\"\/images\/hatchpic.jpg\"><br>\n      Louse hatching from egg<\/a--><\/font><\/td>\n    <td>\n    <font face=\"Arial\" style=\"font-size: 9pt\"><a href=\"\/images\/nitcase.jpg\" target=\"_blank\" rel=\"noopener noreferrer\">\n    <img loading=\"lazy\" decoding=\"async\" src=\"\/images\/tn_nitcase.jpg\" width=\"98\" height=\"72\"><\/a><a href=\"\/images\/hatchpic.jpg\"><br>\n      Nit casings on a hairshaft<\/a><\/font><\/td>\n  <\/tr>\n  <tr>\n    <td align=\"CENTER\" width=\"100%\" colspan=\"4\" bgcolor=\"#FAECFD\" height=\"32\">\n    <font face=\"Arial\" style=\"font-size: 6pt\">&nbsp;<\/font><font face=\"Arial\"><span style=\"font-size: 6pt\">\n    <\/span><font size=\"2\">Images below appear courtesy of Iowa\n      State University<\/font><\/font><\/td>\n  <\/tr>\n  <tr>\n    <td>\n    <font face=\"Arial\" style=\"font-size: 9pt\"><a href=\"\/images\/pedhclawclose.jpg\" target=\"_blank\" rel=\"noopener noreferrer\">\n    <img loading=\"lazy\" decoding=\"async\" border=\"0\" src=\"\/images\/pedhclawclose_tn.jpg\" width=\"96\" height=\"90\"><\/a><a href=\"\/images\/pedhclawclose.jpg\"><br>\n      Pediculus humanus claw<\/a><\/font><\/td>\n    <td>\n    <font face=\"Arial\" style=\"font-size: 9pt\"><a href=\"\/images\/pedhdorsalventral.jpg\" target=\"_blank\" rel=\"noopener noreferrer\">\n    <img loading=\"lazy\" decoding=\"async\" border=\"0\" src=\"\/images\/pedhdorsalventral_tn.jpg\" width=\"96\" height=\"84\"><\/a><a href=\"\/images\/pedhdorsalventral.jpg\"><br>\n      Dorsal and ventral views<\/a><br>\n    <a href=\"\/images\/pedhdorsalventral.jpg\">of Pediculus humanus<\/a><\/font><\/td>\n    <td>\n    <font face=\"Arial\" style=\"font-size: 9pt\"><a href=\"\/images\/pedhdorslat.jpg\" target=\"_blank\" rel=\"noopener noreferrer\">\n    <img loading=\"lazy\" decoding=\"async\" border=\"0\" src=\"\/images\/pedhdorslat_tn.jpg\" width=\"96\" height=\"69\"><\/a><a href=\"\/images\/pedhdorslat.jpg\"><br>\n      Dorsal and lateral views<\/a><br>\n    <a href=\"\/images\/pedhdorslat.jpg\">of Pediculus humanus<\/a><\/font><font style=\"font-size: 9pt\">\n    <\/font>\n    <\/td>\n    <td>\n    <font face=\"Arial\" style=\"font-size: 9pt\"><a href=\"\/images\/pedhentire.jpg\" target=\"_blank\" rel=\"noopener noreferrer\">\n    <img loading=\"lazy\" decoding=\"async\" border=\"0\" src=\"\/images\/pedhentire_tn.jpg\" width=\"96\" height=\"47\"><\/a><a href=\"\/images\/pedhentire.jpg\"><br>\n      Whole body view<\/a><br>\n    <a href=\"\/images\/pedhentire.jpg\">of Pediculus humanus<\/a><\/font><\/td>\n  <\/tr>\n  <tr>\n    <td>\n    <font face=\"Arial\" style=\"font-size: 9pt\"><a href=\"\/images\/pedhhead-labelled.jpg\" target=\"_blank\" rel=\"noopener noreferrer\">\n    <img loading=\"lazy\" decoding=\"async\" border=\"0\" src=\"\/images\/pedhhead-labelled_tn.jpg\" width=\"96\" height=\"65\"><\/a><a href=\"\/images\/pedhhead-labelled.jpg\"><br>\n      Human head louse close-up<\/a><\/font><\/td>\n    <td>\n    <font face=\"Arial\" style=\"font-size: 9pt\">\n    <a target=\"_blank\" href=\"\/images\/pedhlateral.jpg\" rel=\"noopener noreferrer\">\n    <img loading=\"lazy\" decoding=\"async\" border=\"0\" src=\"\/images\/pedhlateral_tn.jpg\" width=\"96\" height=\"71\"><br>\n      Lateral\n      view of<br>\n    Pediculus humanus<\/a><\/font><\/td>\n    <td>\n    <font face=\"Arial\" style=\"font-size: 9pt\"><a href=\"\/images\/pedhlicewdime.jpg\" target=\"_blank\" rel=\"noopener noreferrer\">\n    <img loading=\"lazy\" decoding=\"async\" border=\"0\" src=\"\/images\/pedhlicewdime_tn.jpg\" width=\"96\" height=\"59\"><\/a><a href=\"\/images\/pedhlicewdime.jpg\"><br>\n      Two head lice with dime<\/a><br>\n    <a href=\"\/images\/pedhlicewdime.jpg\">for size comparison<\/a><\/font>\n    <\/td>\n    <td>\n    <font face=\"Arial\" style=\"font-size: 9pt\"><a href=\"\/images\/pedhventral.jpg\" target=\"_blank\" rel=\"noopener noreferrer\">\n    <img loading=\"lazy\" decoding=\"async\" border=\"0\" src=\"\/images\/pedhventral_tn.jpg\" width=\"93\" height=\"89\"><\/a><a href=\"\/images\/pedhventral.jpg\"><br>\n      Ventral view of<\/a><br>\n    <a href=\"\/images\/pedhventral.jpg\">Pediculus humanus<\/a><\/font><\/td>\n  <\/tr>\n  <tr>\n    <td width=\"100%\" colspan=\"4\" bgcolor=\"#FAECFD\"><font face=\"Arial\">\n    <span style=\"font-size: 6pt\"><br>\n      <\/span><font size=\"2\">Next 3 images below appear with permission from  <a href=\"http:\/\/www.entodermoscopy.net\/index.php\/en\/bibliography\" target=\"_blank\" rel=\"noopener noreferrer\">Dr. Gaetano Scanni<\/a> <br>&#8220;Feces of Pediculus capitis humanus as sign of viability of the louse.&#8221; <i>Eur. J. Ped. Dermatol.<\/i> 17, 77-80, 2007.<\/font><span style=\"font-size: 6pt\"><br>\n&nbsp; <\/span><\/font><\/td>\n  <\/tr>\n  \n  <tr>\n    <td>\n    <font face=\"Arial\" style=\"font-size: 9pt\"><a href=\"\/faq\/scanni\/scanni1.jpg\" target=\"_blank\" rel=\"noopener noreferrer\">\n    <img loading=\"lazy\" decoding=\"async\" src=\"\/faq\/scanni\/scanni1.jpg\" width=\"96\" height=\"68\"><\/a><a href=\"\/faq\/scanni\/scanni1.jpg\"><br>\n      Pediculus &amp; Feces (Faeces)<\/a><br><a href=\"http:\/\/www.entodermoscopy.net\/index.php\/en\/bibliography\" target=\"_blank\" rel=\"noopener noreferrer\">Dr. Gaetano Scanni<\/a><\/font><br><br><\/td>\n    <td>\n    <font face=\"Arial\" style=\"font-size: 9pt\"><a href=\"\/faq\/scanni\/scanni2.jpg\" target=\"_blank\" rel=\"noopener noreferrer\">\n    <img loading=\"lazy\" decoding=\"async\" src=\"\/faq\/scanni\/scanni2.jpg\" width=\"96\" height=\"68\"><\/a><a href=\"\/faq\/scanni\/scanni2.jpg\"><br>\n      Pediculus &amp; Feces (Faeces)<\/a><br><a href=\"http:\/\/www.entodermoscopy.net\/index.php\/en\/bibliography\" target=\"_blank\" rel=\"noopener noreferrer\">Dr. Gaetano Scanni<\/a><\/font><br><br><\/td>\n    <td>\n    <font face=\"Arial\" style=\"font-size: 9pt\"><a href=\"\/faq\/scanni\/scanni3.jpg\" target=\"_blank\" rel=\"noopener noreferrer\">\n    <img loading=\"lazy\" decoding=\"async\" src=\"\/faq\/scanni\/scanni3.jpg\" width=\"96\" height=\"68\"><\/a><a href=\"\/faq\/scanni\/scanni3.jpg\"><br>\n      Pediculus &amp; Feces (Faeces)<\/a><br><a href=\"http:\/\/www.entodermoscopy.net\/index.php\/en\/bibliography\" target=\"_blank\" rel=\"noopener noreferrer\">Dr. Gaetano Scanni<\/a><\/font><br><br><\/td>\n      <td><br><\/td>\n    \n  <\/tr>\n  <\/tbody><\/table>\n  <\/div>\n","protected":false},"excerpt":{"rendered":"<p>Images &amp; Biology of Head Lice Images below appear courtesy of Rick Speare Images below appear courtesy of William B. Swain Images below appear courtesy of Dr. Gaetano Scanni Head Lice of Different Sizes Lice of different sizes &nbsp; Head louse Adult female &amp; adult male Nymph (newborn louse) &amp; adult louse Tarsal claw of &hellip;<\/p>\n","protected":false},"author":1,"featured_media":0,"parent":2042,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"_genesis_hide_title":false,"_genesis_hide_breadcrumbs":false,"_genesis_hide_singular_image":false,"_genesis_hide_footer_widgets":false,"_genesis_custom_body_class":"","_genesis_custom_post_class":"","_genesis_layout":"content-sidebar","footnotes":""},"class_list":{"0":"post-2343","1":"page","2":"type-page","3":"status-publish","5":"entry"},"featured_image_src":null,"featured_image_src_square":null,"jetpack_sharing_enabled":true,"jetpack_likes_enabled":false,"amp_enabled":true,"_links":{"self":[{"href":"https:\/\/www.headlice.org\/comb\/wp-json\/wp\/v2\/pages\/2343","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.headlice.org\/comb\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/www.headlice.org\/comb\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/www.headlice.org\/comb\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.headlice.org\/comb\/wp-json\/wp\/v2\/comments?post=2343"}],"version-history":[{"count":14,"href":"https:\/\/www.headlice.org\/comb\/wp-json\/wp\/v2\/pages\/2343\/revisions"}],"predecessor-version":[{"id":3362,"href":"https:\/\/www.headlice.org\/comb\/wp-json\/wp\/v2\/pages\/2343\/revisions\/3362"}],"up":[{"embeddable":true,"href":"https:\/\/www.headlice.org\/comb\/wp-json\/wp\/v2\/pages\/2042"}],"wp:attachment":[{"href":"https:\/\/www.headlice.org\/comb\/wp-json\/wp\/v2\/media?parent=2343"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}