Pubic Louse (Crab Louse)

Natural Habitat

Exclusively found on the coarse body hair of humans, most commonly in the pubic region, but occasionally on eyelashes, eyebrows, beard, chest, or armpit hair.

Diet & Feeding

Hematophagous (feeds exclusively on human blood).

Behavior Patterns

They grasp coarse hair shafts with specialized claws that resemble crab pincers. They are relatively immobile compared to other lice and remain attached to a host their entire lives, laying eggs (nits) on the hair shaft near the skin.

Risks & Benefits

Risks: Causes intense itching (pruritus) due to an allergic reaction to their saliva. Scratching can lead to secondary bacterial infections. They are usually transmitted through sexual contact. Benefits: None known to humans or the broader ecosystem.

Identified on: 2/14/2026