Sucking lice are wingless, flat-bodied insects that look much like chewing lice. The head, however, is narrower than the thorax, and the mouthparts are fitted for piercing the skin and sucking blood rather than chewing. The name derivation has to do with an abdomen that lacks any appendages (they do not possess any stingers). Sucking lice develop with incomplete metamorphosis. They are parasitic on mammals and never attack birds. In addition to possessing sucking rather than chewing mouthparts, these can be separated from chewing lice by their more conical head and reduced eyes.
