Crab Louse, Female

This is a photomicrograph of a female pubic louse. The condition known as "crabs" is so named because of the resemblance of a pubic louse to a crab. The bodies of pubic lice are shorter and rounder than those of head lice. (Courtesy of the Centers for Disease Control.)

Pubic Louse-Male

This is a photomicrograph of a male pubic louse. The condition known as "crabs" is so named because of the resemblance of a pubic louse to a crab. The bodies of pubic lice are shorter and rounder than those of head lice.

Crab Lice

This photograph shows pubic lice clinging to individual hairs (the small, whitish specks). The reddish, crusted areas with scabs (excoriated areas) are caused by scratching. (Courtesy of the Centers for Disease Control.)

Head Louse and Pubic Louse

This picture compares the relative size and shape of the head louse and the pubic louse.