Human Head Louse

Scientific Name: Pediculus humanus capitis

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

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

Human Head Louse

Natural Habitat

Exclusively on the human scalp, living near the hair base for warmth and food access.

Diet & Feeding

Obligate hematophagy; 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 cement their eggs (nits) to hair shafts and have a life cycle consisting of egg, nymph, and adult stages.

Risks & Benefits

Risk: Causes pediculosis (infestation), leading to intense itching, scalp irritation, and potential secondary bacterial infections from scratching. Benefit: None to humans; they are strictly parasitic pests.

Identified on: 12/30/2025