Pubic Louse
Scientific Name: Pthirus pubis
Order & Family: Order: Psocodea (formerly Anoplura); Family: Pthiridae
Size: 1.1 mm to 1.8 mm (roughly the size of a pinhead or sesame seed)
Natural Habitat
Exclusively found on human hosts, primarily inhabiting coarse bodily hair such as pubic hair, but occasionally eyebrows, eyelashes, or armpit hair.
Diet & Feeding
Obligate hematophages; they feed exclusively on human blood several times a day to survive.
Behavior Patterns
They are slow-moving and use specialized crab-like claws to grip hair shafts. They cannot jump or fly. They undergo three nymphal stages before reaching adulthood and lay eggs (nits) that are firmly glued to the base of hairs.
Risks & Benefits
Risks include intense itching (pruritus) due to an allergic reaction to their saliva, and potential secondary bacterial skin infections from scratching. They are typically transmitted through close physical/sexual contact or occasionally through infested bedding or clothing. There are no known ecological benefits.
Identified on: 1/1/2026