Pediculosis is an infestation of lice—blood-feeding ectoparasitic insects of the order Phthiraptera. The condition can occur in almost any species of warm-blooded animal (i.e., mammals and birds), including humans. Although "pediculosis" in humans may properly refer to lice infestation of any part of the body, the term is sometimes used loosely to refer to pediculosis capitis, the infestation of the human head with the specific head louse.