Human Head Louse

Scientific Name: Pediculus humanus capitis

Order & Family: Order: Psocodea; Family: Pediculidae

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

Human Head Louse

Natural Habitat

Found exclusively on the human scalp and hair, most commonly behind the ears and at the nape of the neck.

Diet & Feeding

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

Behavior Patterns

They are wingless, crawling insects that cannot jump or fly. They attach their eggs (nits) to hair shafts with a waterproof glue-like substance and depend entirely on the host's body heat for survival.

Risks & Benefits

They do not transmit diseases. However, they cause intense itching, which can lead to secondary skin infections from scratching. They are considered a social nuisance but provide no ecosystem benefits.

Identified on: 4/30/2026