Family Phthiriidae is a group of parasitic lice that feed exclusively on humans. These lice are commonly known as pubic lice, crab lice, or simply crabs. The term "crab" comes from their crab-like appearance and their ability to move sideways, like crabs. Other synonyms for the family Phthiriidae include Pthiridae, Pediculidae, and Anoplura. These lice can be found in the pubic area, but can also infest other body hair, including armpits, beard, and mustache. Pubic lice are transmitted through sexual contact or through sharing of infested clothing or bedding. Treatment typically involves applying a medicated cream or using special shampoo to kill the lice and their eggs.