Human Head Louse

Scientific Name: Pediculus humanus capitis

Order & Family: Order: Psocodea; Family: Pediculidae

Size: 2mm to 3mm in length (roughly the size of a sesame seed).

Human Head Louse

Natural Habitat

Exclusively the human scalp and hair strands, where they stay close to the skin for warmth and food.

Diet & Feeding

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

Behavior Patterns

They are wingless and cannot jump; they move by crawling. Females lay eggs (nits) and cement them to hair shafts near the scalp. They cannot survive more than 24-48 hours off a human host.

Risks & Benefits

They cause intense itching and scalp irritation but do not transmit diseases. They are considered a nuisance rather than a medical threat, though secondary skin infections can occur from scratching.

Identified on: 1/11/2026