Human Head Louse

Scientific Name: Pediculus humanus capitis

Order & Family: Order: Psocodea (formerly Anoplura); Family: Pediculidae

Size: 2mm to 3mm (approximately the size of a sesame seed)

Human Head Louse

Natural Habitat

The scalp and hair of humans; most common behind the ears and at the neckline.

Diet & Feeding

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

Behavior Patterns

They are wingless and cannot jump or fly; they move by crawling. They attach their eggs (nits) to the base of hair shafts with a waterproof glue-like substance. They cannot survive for more than 24-48 hours off a human host.

Risks & Benefits

While they Cause intense itching (pruritus) and social distress, they are not known to transmit diseases. Scratching can lead to secondary bacterial skin infections.

Identified on: 5/21/2026