Lice

Lice infestation, or pediculosis, is a condition in which parasitic insects feed on human blood.  There are 3 types of lice that infest humans: head lice (Pediculus humanus capitis), body lice (Pediculus humanus humanus), and pubic lice (Pthirus pubis).

Lice are translucent ectoparasites ( Image 1) that depend on human blood for survival.  They have "crab-like" claws ( Image 2) that help them attach to human hair and specialized mouthparts that pierce human skin.  Lice infestation occurs when adult female lice lay eggs, known as nits ( Image 3), on either hair shafts (head and pubic lice) or clothing and bedding (body lice).  The nits remain firmly attached until they hatch into nymphs in about a week.  Nymphs mature into adult lice and live for about a month, feeding on human blood daily.  Without a host, lice die in 2-3 days.