Many of the chewing lice are highly host specific, but a few may occur on a variety of not more than a half dozen related host species. They feed on skin (epidermal cells), hair, feathers, body oils and secretions, dried blood (wounds), and even other ectoparasites, such as mites. Chewing lice are unable to survive for more than a day or two off the host and their dispersal is through direct contact of host animals.