Pubic Louse (Crab Louse)

Natural Habitat

Exclusively found on the human body, specifically in coarse hair regions such as the pubic area, eyelashes, eyebrows, beard, mustache, armpits, and chest hair. They cannot survive for long away from the warmth and humidity of the human body.

Diet & Feeding

Hematophagous, meaning they feed exclusively on human blood. They use their specialized mouthparts to pierce the skin and suck blood several times a day.

Behavior Patterns

They are ectoparasites that cling to hair shafts using large crab-like claws on their second and third pairs of legs (giving them their 'crab' nickname). They move slowly and do not jump or fly. Their life cycle involves three stages: egg (nit), nymph, and adult. Nymphs molt three times before becoming adults.

Risks & Benefits

Risks: They cause intense itching (pruritus) due to an allergic reaction to their saliva. Scratching can lead to secondary bacterial skin infections. While annoying and socially stigmatizing, they are generally not known to transmit disease, unlike body lice. Benefits: None known to humans or the ecosystem as they are obligate parasites.

Identified on: 2/14/2026