What is Louse?
{{Taxobox | name = Phthiraptera | image = Fahrenholzia pinnata.JPG | image_width = 170px | image_caption = ''Fahrenholzia pinnata'' | regnum = [[Animal]]ia | phylum = [[Arthropod]]a | classis = [[Insect]]a | subclassis = [[Pterygota]] | infraclassis = [[Neoptera]] | ordo = '''Phthiraptera''' | ordo_authority = [[Ernst Haeckel|Haeckel]], 1896 | subdivision_ranks = Suborders | subdivision = }} '''Lice''' (singular: '''louse'''), are wingless [[insect]]s that live in [[hair]]. They are all external [[parasite]]s on every species of [[bird]] and most [[mammals|mammalian]] orders. They are not found on [[Monotreme]]s and a few [[eutheria]]n orders, namely [[bat]]s (Chiroptera), [[Cetacea|whales, dolphins and porpoises]] (Cetacea) and [[pangolin]]s (Pholidota). There are more than 3,000 different [[species]]; three are classified as human lice. == Description == Lice spend their whole life on the host. They are adapted to keep close contact with the host. These adaptations are reflected in their size (0.5–8&nbsp;[[Millimetre|mm]]), stout legs, and claws which are adapted to clinging tightly to hair, fur and feathers. They are also wingless and flattened. Lice feed on [[skin]] (epidermal) debris, [[feather]] parts, [[Sebaceous gland|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's 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 more yellow. Lice are very annoying and are difficult to remove, but not impossible. The process is called ''nit-picking'', and is often done with a close-toothed metal comb. For humans, anti-insect shampoos are available. == Classification == The order has traditionally been divided into two suborders; the ''sucking lice'' (Anoplura) and ''chewing lice'' (Mallophaga). Four su