The lice are a small order of exclusively parasitic insects which live in the fur or plumage of mammals and birds.

They are small, flattened insects lacking wings, and being equipped with short, stout legs with curved hooks used to cling to the host. The eggs are cemented to the host’s hairs or feathers, and both nymphs and imagines feed on either dead skin, hair, feathers, oily secretions or blood from the host. Lice are generally very host specific, and humans are host to two species: the pubic louse (Phthirus pubis), and the head and body louse (two ecologically separate subspecies of Pediculus humanus).