AskDefine | Define louse

Dictionary Definition



1 wingless usually flattened blood-sucking insect parasitic on warm-blooded animals [syn: sucking louse]
2 a person who has a nasty or unethical character undeserving of respect [syn: worm, insect, dirt ball]
3 any of several small insects especially aphids that feed by sucking the juices from plants [syn: plant louse]
4 wingless insect with mouth parts adapted for biting; mostly parasitic on birds [syn: bird louse, biting louse] [also: lice (pl)]

User Contributed Dictionary



lows(e) < lūs < *lus-.



  1. A small parasitic wingless insect of the order Phthiraptera.




  1. To remove lice from the body of a person or animal; to delouse



worthless person

Extensive Definition

Lice (singular: louse), (order Phthiraptera), also known as fly babies, are an order of over 3,000 species of wingless insects; three of which are classified as human disease agents. They are obligate ectoparasites of every avian and most mammalian orders. They are not found on Monotremes (the platypus and the echidnas or spiny anteaters) and a few eutherian orders, namely the bats (Chiroptera), whales, dolphins and porpoises (Cetacea) and pangolins (Pholidota).


As lice spend their entire lives on the host, they have developed adaptations which enable them to maintain close contact with the host. These adaptations are reflected in their size (0.5–8 mm), stout legs, and claws which are adapted to cling tightly to hair, fur and feathers, and that they are wingless and dorsoventrally flattened.
Lice feed on skin (epidermal) debris, feather parts, sebaceous secretions and blood. A louse's color varies from pale beige to dark grey; however, if feeding on blood, it may become considerably darker.
A louse egg is commonly called a nit. Lice attach their eggs to their host's hair with specialized saliva which results in a bond that is very difficult to separate without specialized products. Living lice eggs tend to be pale white. Dead lice eggs are orangeish.


The order has traditionally been divided into two suborders; the sucking lice (Anoplura) and chewing lice (Mallophaga), however, recent classifications suggest that the Mallophaga are paraphyletic and four suborders are now recognised:
It has been suggested that the order is contained by the Troctomorpha suborder of Psocoptera.

Lice and humans

Humans are unique in that they host three different kinds of lice: head lice, body lice (which live mainly in clothing), and pubic lice. The DNA differences between head lice and body lice provide corroborating evidence that humans started wearing clothes approximately 72,000 years ago.
Recent DNA evidence suggests that pubic lice spread to the ancestors of humans approximately 3.3 million years ago from the ancestors of gorillas by sharing the same bed or other communal areas with them, and are more closely related to lice endemic to gorillas than to other lice species infesting humans.


External links


louse in Arabic: قمل
louse in Min Nan: Sat-bó
louse in Breton: laou
louse in Danish: Lus (insekt)
louse in German: Tierläuse
louse in Spanish: Phthiraptera
louse in Esperanto: Laŭso
louse in French: Pou
louse in Ido: Lauso
louse in Italian: Pidocchio
louse in Hebrew: כינים
louse in Hungarian: Tetű
louse in Dutch: Luis
louse in Japanese: シラミ
louse in Norwegian: Lus
louse in Polish: Wesz
louse in Portuguese: Piolho
louse in Finnish: Täit
louse in Swedish: Löss
louse in Turkish: Kımıl

Synonyms, Antonyms and Related Words

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