Editing Louse (section)

==In human culture==
{{About||information about human infestation|Pediculosis|information on treatment|Treatment of human head lice}}

===In social history===

[[File:Louse diagram, Micrographia, Robert Hooke, 1667.jpg|thumb|upright=0.7|left|Drawing of a louse clinging to a human hair. [[Robert Hooke]], ''[[Micrographia]]'', 1667]]

Lice have been intimately associated with human society throughout history. In the [[Middle Ages]], they were essentially ubiquitous. At the death of [[Thomas Becket]], [[Archbishop of Canterbury]] in 1170, it was recorded that "The vermin boiled over like water in a simmering cauldron, and the onlookers burst into alternate weeping and laughing".<ref name=Kowalski>{{cite journal | vauthors = Kowalski TJ, Agger WA | title = Art supports new plague science | journal = Clinical Infectious Diseases | volume = 48 | issue = 1 | pages = 137–8 | date = January 2009 | pmid = 19067623 | doi = 10.1086/595557 | doi-access = free }}</ref> The clergy often saw lice and other parasites as a constant reminder of human frailty and weakness. Monks and nuns would purposely ignore grooming themselves and suffer from infestations to express their religious devotion.<ref>{{Cite web |last=Harvey |first=Katherine |date=2019-04-09 |title=Medieval people were surprisingly clean (apart from the clergy) |url=https://aeon.co/essays/medieval-people-were-surprisingly-clean-apart-from-the-clergy |access-date=2022-10-13 |website=[[Aeon magazine|Aeon]] |language=en}}</ref> A mediaeval treatment for lice was an [[ointment]] made from pork grease, [[incense]], [[lead]], and [[aloe]].<ref>{{cite book | vauthors = Elliott L |title=Clothing in the Middle Ages |url=https://books.google.com/books?id=qtq_WSpdo0gC&pg=PT29 |year=2004 |publisher=Crabtree |isbn=978-0-7787-1351-7 |page=29}}</ref>

[[Robert Hooke]]'s 1667 book, ''[[Micrographia|Micrographia: or some physiological descriptions of minute bodies made by magnifying glasses with observations and Inquiries thereupon]]'', illustrated a human louse, drawn as seen down an early [[microscope]].<ref>{{cite web | vauthors = Hooke R |title=Microscopic view of a louse |url=http://prints.royalsociety.org/art/580831/microscopic-view-of-a-louse |publisher=The Royal Society |access-date=17 October 2015}}</ref>

[[Margaret Cavendish]]'s satirical ''[[The Description of a New World, Called The Blazing-World]]'' (1668) has "Lice-men" as "mathematicians", investigating nature by trying to weigh the air like the real scientist [[Robert Boyle]].<ref name="Sarasohn2010">{{cite book | vauthors = Sarasohn LT |title=The Natural Philosophy of Margaret Cavendish: Reason and Fancy During the Scientific Revolution |url=https://books.google.com/books?id=sE0XnNgF9ZoC&pg=PA167 |year=2010 |publisher=JHU Press |isbn=978-0-8018-9443-5|pages=165–167 |quote=The Bear-men were to be her Experimental Philosophers, the Bird-men her Astronomers, the Fly- Worm- and Fish-men her Natural Philosophers, the Ape-men her Chymists, the Satyrs her Galenick Physicians, the Fox-men her Politicians, the Spider- and Lice-men her Mathematicians, the Jackdaw- Magpie- and Parrot-men her Orators and Logicians, the Gyants her Architects, &c.}}</ref><ref>{{cite book| vauthors = Cavendish M |title=The Description of a New World, Called the Blazing-World|date=1668|publisher=A. Maxwell|url=http://digital.library.upenn.edu/women/newcastle/blazing/blazing.html}}</ref>

In 1935 the Harvard medical researcher [[Hans Zinsser]] wrote the book ''[[Rats, Lice and History]]'', alleging that both body and head lice transmit typhus between humans.<ref>{{cite book | vauthors = Zinsser H |title=Rats, Lice and History |date=2007 |orig-year=1935 |publisher=Transaction Publishers |isbn=978-1-4128-0672-5}}</ref> Despite this, the modern view is that only the body louse can transmit the disease.<ref>{{cite web | vauthors = Altschuler DZ |title=Zinsser, Lice and History |url=http://www.headlice.org/faq/disease/zinsser.htm |publisher=HeadLice.org |access-date=19 October 2015 |date=1990}}</ref>

[[File:Jan Siberechts "Cour de ferme" détail Scène d'épouillage.jpg|thumb|upright|Detail showing delousing from [[Jan Siberechts]]' painting ''Cour de ferme'' ("Farmyard"), 1662]]

Soldiers in the trenches of the [[First World War]] suffered severely from lice, and the [[typhus]] they carried. The Germans boasted that they had lice under effective control, but themselves suffered badly from lice in the [[Second World War]] on the Eastern Front, especially in the [[Battle of Stalingrad]]. "[[Delousing]]" became a [[euphemism]] for the extermination of Jews in [[concentration camp]]s such as [[Auschwitz]] under the Nazi regime.<ref>{{cite web | vauthors = Evans RJ |author-link1=Richard J. Evans |title=The Great Unwashed |url=http://www.gresham.ac.uk/lectures-and-events/the-great-unwashed |publisher=Gresham College |access-date=17 October 2015}}</ref>

In the psychiatric disorder [[delusional parasitosis]], patients express a persistent irrational fear of animals such as lice and mites, imagining that they are continually infested and complaining of itching, with "an unshakable false belief that live organisms are present in the skin".<ref>{{cite web | vauthors = Weinstein P | date = 26 February 2013 | title = 'The Great Unwashed': Entomophobia/Delusionary Parasitosis; Illusionary Parasitosis | url = http://medent.usyd.edu.au/fact/delpara.htm | publisher = University of Sydney Department of Medical Entomology | access-date = 17 October 2015 | series = The Great Plagues: Epidemics in History from the Middle Ages to the Present Day | archive-date = 17 May 2016 | archive-url = https://web.archive.org/web/20160517005233/http://medent.usyd.edu.au/fact/delpara.htm | url-status = dead }}</ref>

===In literature and folklore===
[[File:Mother Louse, Alewife Wellcome L0000658.jpg|thumb|left|upright|Mother Louse, a notorious [[Alewife (trade)|alewife]] in Oxford during the mid-18th century, shown with three lice as a [[coat of arms]]. Image by [[David Loggan]].<ref name="White1859">{{cite book|url=https://books.google.com/books?id=l68ZhT2agbEC&pg=PA275|title=Notes & Queries|publisher=Oxford University Press|year=1859|pages=275–276| vauthors = White W }}</ref><ref>{{Cite web|publisher=University of York| vauthors = Pierce H |title=Unseemly pictures: political graphic satire in England, c. 1600-c. 1650|date=2004|url=http://etheses.whiterose.ac.uk/9864/1/423697_vol1.pdf}}</ref>]]

[[James Joyce]]'s 1939 book ''[[Finnegans Wake]]'' has the character Shem the Penman infested with "[[foxtrot]]ting fleas, the lieabed lice,&nbsp;... bats in his belfry".<ref>{{cite book | vauthors = Joyce J | author-link1 = James Joyce |title=Finnegans Wake |date=1939 |publisher=Faber |page=180}}</ref>

Clifford E. Trafzer's ''A [[Chemehuevi]] Song: The Resilience of a [[Southern Paiute]] Tribe'' retells the story of Sinawavi ([[Coyote]])'s love for Poowavi (Louse). Her eggs are sealed in a basket woven by her mother, who gives it to Coyote, instructing him not to open it before he reaches home. Hearing voices coming from it, however, Coyote opens the basket and the people, the world's first human beings, pour out of it in all directions.<ref name="Trafzer2015">{{cite book | vauthors = Trafzer CE |title=A Chemehuevi Song: The Resilience of a Southern Paiute Tribe |url=https://books.google.com/books?id=GA81CgAAQBAJ&pg=PA24 |date=2015 |publisher=University of Washington Press |isbn=978-0-295-80582-5 |pages=22–25}}</ref>

The Irish songwriter John Lyons (b. 1934) wrote the popular<ref name=Clare/> song ''The Kilkenny Louse House''. The song contains the lines "Well we went up the stairs and we put out the light, Sure in less than five minutes, I had to show fight. For the fleas and the bugs they collected to march, And over me stomach they formed a great arch". It has been recorded by Christie Purcell (1952), Mary Delaney on ''From Puck to Appleby'' (2003), and the [[Dubliners]] on ''[[Double Dubliners]]'' (1972) among others.<ref name=Clare>{{cite web | vauthors = Carroll J |title=Songs of Clare: The Kilkenny Louse House |url=http://www.clarelibrary.ie/eolas/coclare/songs/cmc/the_kilkenny_louse_house_jlyons.htm |publisher=Clare Library |access-date=19 October 2015}}</ref><ref>{{cite web |vauthors=Scott B |title=My Colleen by the Shore |url=http://www.veteran.co.uk/VT149CD%20Paginated%20booklet%20pages.pdf |publisher=Veteran |year=2013 |access-date=25 October 2015 |archive-date=4 March 2016 |archive-url=https://web.archive.org/web/20160304000329/http://www.veteran.co.uk/VT149CD%20Paginated%20booklet%20pages.pdf |url-status=dead }}</ref>

[[Robert Burns]] dedicated a poem to the louse, inspired by witnessing one on a lady's bonnet in church: "Ye ugly, creepin, blastid wonner, Detested, shunn'd, by saint and sinner, How dare ye set your fit upon her, sae fine lady! Gae somewhere else, and seek your dinner on some poor body." [[John Milton]] in ''[[Paradise Lost]]'' mentioned the biblical plague of lice visited upon pharaoh: "Frogs, lice, and flies must all his palace fill with loathed intrusion, and filled all the land." [[John Ray]] recorded a Scottish proverb, "Gie a beggar a bed and he'll repay you with a Louse." In [[Shakespeare]]'s ''[[Troilus and Cressida]]'', [[Thersites]] compares [[Menelaus]], brother of [[Agamemnon]], to a louse: "Ask me not what I would be, if I were not Thersites; for I care not to be the louse of a lazar, so I were not Menelaus."<ref>{{Cite thesis |title=Insect Life in the Poetry and Drama of England: With Special Reference to Poetry | vauthors = Twinn CR |publisher=University of Ottawa | degree= PhD |year=1942 |hdl=10393/21088  }}</ref>

===In science===
The human [[body louse]] ''Pediculus humanus humanus'' has the smallest insect [[genome]] known,<ref>{{cite journal | vauthors = Kirkness EF, Haas BJ, Sun W, Braig HR, Perotti MA, Clark JM, Lee SH, Robertson HM, Kennedy RC, Elhaik E, Gerlach D, Kriventseva EV, Elsik CG, Graur D, Hill CA, Veenstra JA, Walenz B, Tubío JM, Ribeiro JM, Rozas J, Johnston JS, Reese JT, Popadic A, Tojo M, Raoult D, Reed DL, Tomoyasu Y, Kraus E, Krause E, Mittapalli O, Margam VM, Li HM, Meyer JM, Johnson RM, Romero-Severson J, Vanzee JP, Alvarez-Ponce D, Vieira FG, Aguadé M, Guirao-Rico S, Anzola JM, Yoon KS, Strycharz JP, Unger MF, Christley S, Lobo NF, Seufferheld MJ, Wang N, Dasch GA, Struchiner CJ, Madey G, Hannick LI, Bidwell S, Joardar V, Caler E, Shao R, Barker SC, Cameron S, Bruggner RV, Regier A, Johnson J, Viswanathan L, Utterback TR, Sutton GG, Lawson D, Waterhouse RM, Venter JC, Strausberg RL, Berenbaum MR, Collins FH, Zdobnov EM, Pittendrigh BR | display-authors = 6 | title = Genome sequences of the human body louse and its primary endosymbiont provide insights into the permanent parasitic lifestyle | journal = Proceedings of the National Academy of Sciences of the United States of America | volume = 107 | issue = 27 | pages = 12168–73 | date = July 2010 | pmid = 20566863 | pmc = 2901460 | doi = 10.1073/pnas.1003379107 | bibcode = 2010PNAS..10712168K | doi-access = free }}</ref> and this louse can transmit certain diseases that the closely related human [[head louse]] (''P. h. capitis'') cannot. With their simple life history and small genomes, the pair make ideal [[model organism]]s to study the [[Molecular biology|molecular mechanisms]] behind the transmission of [[pathogen]]s and [[Vector (epidemiology)|vector]] [[Natural competence|competence]].<ref>{{cite journal | vauthors = Pittendrigh BR, Berenbaum MR, Seufferheld MJ, Margam VM, Strycharz JP, Yoon KS, Sun W, Reenan R, Lee SH, Clark JM | display-authors = 6 | title = Simplify, simplify: Lifestyle and compact genome of the body louse provide a unique functional genomics opportunity | journal = Communicative & Integrative Biology | volume = 4 | issue = 2 | pages = 188–91 | date = March 2011 | pmid = 21655436 | pmc = 3104575 | doi = 10.4161/cib.4.2.14279 }}</ref>

Lice have been the subject of significant [[DNA]] research in the 2000s that led to discoveries on human evolution. The three species of sucking lice that parasitize human beings belong to two genera, ''[[Pediculus]]'' and ''[[Pthirus]]'': [[head lice]] (''Pediculus humanus capitis''), [[body lice]] (''Pediculus humanus humanus''), and [[pubic lice]] (''Pthirus pubis''). Human head and body lice (genus ''Pediculus'') share a common ancestor with chimpanzee lice, while pubic lice (genus ''Pthirus'') share a common ancestor with gorilla lice. Using phylogenetic and cophylogenetic analysis, Reed et al. hypothesized that ''Pediculus'' and ''Pthirus'' are sister taxa and monophyletic.<ref name="Reed D.L. 2007"/> In other words, the two genera descended from the same common ancestor. The age of divergence between ''Pediculus'' and its common ancestor is estimated to be 6-7 million years ago, which matches the age predicted by [[Chimpanzee–human last common ancestor|chimpanzee-hominid divergence]].<ref name="Reed D.L. 2007"/> Because parasites rely on their hosts, host{{endash}}parasite cospeciation events are likely.

Genetic evidence suggests that human ancestors acquired pubic lice from [[gorilla]]s approximately 3-4 million years ago.<ref name="Reed D.L. 2007">{{cite journal | vauthors = Reed DL, Light JE, Allen JM, Kirchman JJ | title = Pair of lice lost or parasites regained: the evolutionary history of anthropoid primate lice | journal = BMC Biology | volume = 5 | issue = 7 | pages = 7 | date = March 2007 | pmid = 17343749 | pmc = 1828715 | doi = 10.1186/1741-7007-5-7 | doi-access = free }}</ref> Unlike the genus ''Pediculus'', the divergence in ''Pthirus'' does not match the age of host divergence that likely occurred 7 million years ago. Reed et al. propose a ''Pthirus'' species host-switch around 3-4 million years ago. While it is difficult to determine if a parasite{{endash}}host switch occurred in evolutionary history, this explanation is the most parsimonious (containing the fewest evolutionary changes).<ref name="Reed D.L. 2007"/>

Additionally, the DNA differences between head lice and body lice provide corroborating evidence that humans used clothing between 80,000 and 170,000 years ago, before leaving Africa.<ref name=Parry>{{cite web | vauthors = Parry W |title=Lice Reveal Clues to Human Evolution |url=http://www.livescience.com/41028-lice-reveal-clues-to-human-evolution.html |publisher=LiveScience |access-date=25 October 2015 |date=7 November 2013}}</ref> Human head and body lice occupy distinct ecological zones: head lice live and feed on the scalp, while body lice live on clothing and feed on the body. Because body lice require clothing to survive, the divergence of head and body lice from their common ancestor provides an estimate of the date of introduction of clothing in human evolutionary history.<ref name=Parry/><ref name="Kittler R. 2003">{{cite journal | vauthors = Kittler R, Kayser M, Stoneking M | title = Molecular evolution of Pediculus humanus and the origin of clothing | journal = Current Biology | volume = 13 | issue = 16 | pages = 1414–7 | date = August 2003 | pmid = 12932325 | doi = 10.1016/S0960-9822(03)00507-4 | s2cid = 15277254 | doi-access = free | bibcode = 2003CBio...13.1414K }}</ref>

The mitochondrial genome of the human species of the body louse (''[[Pediculus humanus humanus]]''), the head louse (''[[Pediculus humanus capitis]]'') and the pubic louse (''[[Pthirus pubis]]'') fragmented into a number of [[minichromosome]]s at least seven million years ago.<ref name=Shao2012>{{cite journal | vauthors = Shao R, Zhu XQ, Barker SC, Herd K | title = Evolution of extensively fragmented mitochondrial genomes in the lice of humans | journal = Genome Biology and Evolution | volume = 4 | issue = 11 | pages = 1088–101 | year = 2012 | pmid = 23042553 | pmc = 3514963 | doi = 10.1093/gbe/evs088 }}</ref> Analysis of mitochondrial DNA in human body and hair lice reveals that greater genetic diversity existed in African than in non-African lice.<ref name="Kittler R. 2003"/><ref name=Light>{{cite journal | vauthors = Light JE, Allen JM, Long LM, Carter TE, Barrow L, Suren G, Raoult D, Reed DL | display-authors = 6 | title = Geographic distributions and origins of human head lice (Pediculus humanus capitis) based on mitochondrial data | journal = The Journal of Parasitology | volume = 94 | issue = 6 | pages = 1275–81 | date = December 2008 | pmid = 18576877 | doi = 10.1645/GE-1618.1 | s2cid = 9456340 }}</ref> Human lice can also shed light on human migratory patterns in prehistory. The dominating theory of [[Anthropology|anthropologists]] regarding human migration is the [[Out of Africa Hypothesis]]. Genetic diversity accumulates over time, and mutations occur at a relatively constant rate. Because there is more genetic diversity in African lice, the lice and their human hosts must have existed in Africa before anywhere else.<ref name=Light/>

=== Woodlouse ===
The name [[woodlouse]] or wood-louse is given to [[crustacean]]s of the [[suborder]] Oniscidea within the [[order (biology)|order]] [[Isopoda]], unrelated to lice. The ''[[Oxford English Dictionary]]''{{'}}s earliest citation of this usage is from 1611.<ref>{{Cite OED|Woodlouse}}</ref>