Pubic louse

Scientific Name: Pthirus pubis

Order & Family: Order: Psocodea, Family: Pthiridae

Size: 1.1 mm to 1.8 mm (roughly the size of a pinhead or a grain of salt)

Pubic louse

Natural Habitat

Exclusively on human hosts, primarily inhabiting pubic hair and surrounding regions, but occasionally found on other coarse body hair like eyelashes or eyebrows.

Diet & Feeding

Obligate hematophage; they feed exclusively on human blood several times a day.

Behavior Patterns

They are relatively immobile and spend their entire life cycle on the host. They attach themselves firmly to hair shafts with specialized claws and use piercing mouthparts to reach capillaries.

Risks & Benefits

Risks: Causes intense itching (pediculosis pubis) due to hypersensitivity to saliva, and can lead to secondary bacterial skin infections from scratching. No known ecosystem benefits; they are considered human parasites.

Identified on: 3/12/2026