Head Louse

Scientific Name: Pediculus humanus capitis

Order & Family: Order: Psocodea, Family: Pediculidae

Size: 2-3 mm (roughly the size of a sesame seed)

Head Louse

Natural Habitat

Exclusively on the human scalp, particularly near the ears and the nape of the neck.

Diet & Feeding

Obligate ectoparasite; feeds exclusively on human blood several times a day.

Behavior Patterns

Wingless and unable to jump; they move by crawling between hair shafts. Females glue eggs (nits) firmly to hair near the scalp. They cannot survive for more than 24-48 hours off a human host.

Risks & Benefits

Risks include intense itching (allergic reaction to saliva), sores from scratching, and secondary bacterial infections. They do not transmit diseases. There are no ecological benefits to humans.

Identified on: 3/2/2026