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. (Image courtesy of the Centers for Disease Control and Prevention.)
Update Date 11/4/2015
Updated by: Jesse Borke, MD, FACEP, FAAEM, Attending Physician at FDR Medical Services/Millard Fillmore Suburban Hospital, Buffalo, NY. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.