Human Head Louse

Scientific Name: Pediculus humanus capitis

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

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

Human Head Louse

Natural Habitat

The scalp and hair of humans; most commonly found behind the ears and near the neckline at the back of the head.

Diet & Feeding

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

Behavior Patterns

They are wingless, crawling insects that cannot jump or fly. They attach their eggs (nits) to hair shafts near the scalp with a waterproof glue-like substance. They spread through direct head-to-head contact.

Risks & Benefits

Risks include intense itching, scalp irritation, and potential secondary bacterial skin infections from scratching. They are not known to transmit systemic diseases. There are no ecological benefits to humans.

Identified on: 4/1/2026