Human Head Louse

Scientific Name: Pediculus humanus capitis

Order & Family: Order Psocodea, Family Pediculidae

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

Human Head Louse

Natural Habitat

Specifically the hair and scalp of humans, most commonly behind the ears and near the neckline.

Diet & Feeding

Obligate blood feeders, consuming human blood several times a day.

Behavior Patterns

They are wingless and cannot jump; they move by crawling. They lay eggs (nits) at the base of hair shafts. They cannot survive for more than 24-48 hours off a human host.

Risks & Benefits

While they cause intense itching and social distress, they are not known to transmit diseases. Risk includes potential secondary skin infections from scratching.

Identified on: 12/28/2025