louse

A secondarily wingless insect, parasitic on warm-blooded vertebrates. Sucking lice (Order: Anoplura) suck blood of mammals; length up to 6 mm/¼ in; bodies flattened, legs with claws for attaching to host; eyes reduced or absent; c.300 species. They include two varieties of human louse: head lice (Pediculus humanus capitis) and body lice (Pediculus humanus humanus), both transmitted by direct contact; lay eggs (nits) on hair and clothing; can transmit typhus and other diseases. Biting lice (Order: Mallophaga) live mostly on birds, have biting mouthparts for feeding on feathers; c.2700 species, a few found on mammals, feeding on hair.

Scientific classification
Kingdom: Animalia Phylum: Arthropoda Subphylum: Hexapoda Class: Insecta Subclass: Pterygota Infraclass: Neoptera Order: Phthiraptera Haeckel, 1896
Suborders
Anoplura (sucking lice) Rhyncophthirina Ischnocera (avian lice) Amblycera (chewing lice)

Lice (singular: louse), also known as fly babies, (order Phthiraptera) are an order of over 3,000 species of wingless phthiraptra. the sucking lice (Anoplura) and chewing lice (Mallophaga), however, recent classifications suggest that the Mallophaga are paraphyletic and four suborders are now recognised:

Anoplura: sucking lice, including head and pubic lice (see also Pediculosis or Head lice) Rhyncophthirina: parasites of elephants and warthogs Ischnocera: avian lice Amblycera: chewing lice, a primitive order of lice

Lice are highly specialized based on the host species and many species specifically only feed on certain areas of their host's body.