Human Head Louse

Scientific Name: Pediculus humanus capitis

Order & Family: Order: Psocodea; Family: Pediculidae

Size: 2.1 mm to 3.3 mm (about the size of a sesame seed)

Human Head Louse

Natural Habitat

The human scalp, specifically residing near the hair shafts where it is warm and humid.

Diet & Feeding

Obligate hematophage; it feeds exclusively on human blood several times a day.

Behavior Patterns

They are wingless and cannot jump or fly; they move through direct head-to-head contact. Eggs (nits) are cemented to hair shafts and hatch in about 8-9 days.

Risks & Benefits

Risks include intense itching (pruritus) due to an allergic reaction to saliva, potential secondary skin infections from scratching, and social distress. They are not known to transmit diseases.

Identified on: 1/10/2026