
Community identification
Pubic Louse (Crab Louse)
Pthirus pubis
- Order & Family
- Order: Psocodea (formerly Anoplura); Family: Pthiridae
- Size
- 1.1 mm to 1.8 mm (roughly the size of a pinhead)
Natural Habitat
Human body hair, most commonly in the pubic region, but can also be found in eyelashes, eyebrows, armpits, or chest hair.
Diet & Feeding
Obligate ectoparasite; feeds exclusively on human blood several times a day.
Behavior Patterns
Crawls from person to person through close physical contact; cannot jump or fly. They cling to hair shafts and lay eggs (nits) at the base of the hair.
Risks & Benefits
Risks include intense itching (pruitus) caused by an allergic reaction to their saliva, and secondary skin infections from scratching. They do not transmit diseases but are a public health nuisance and signify the need for medical treatment.