Bird Louse, a common name for several small, biting insects that are parasites on warm-blooded animals, particularly birds. They have no wings, and their biting mouth parts distinguish them from true lice, which suck blood. Bird lice eat feathers, hair, and cast-off skin cells. Some lice on birds obtain blood by chewing young feathers. Almost all domestic animals are hosts for at least one species of bird louse, and chickens and other fowl are attacked by several kinds. Unlike true lice, bird lice do not carry infectious diseases.

Bird lice make up the family Philopteridae of the order Mallophaga.