Linen Head Louse
Scientific Name: Pediculus humanus capitis
Order & Family: Order Psocodea (formerly Phthiraptera), Family Pediculidae
Size: 2.1 mm to 3.3 mm (roughly the size of a sesame seed)
Natural Habitat
The human scalp and hair, where they stay close to the skin for warmth and food.
Diet & Feeding
Obligate parasites that feed exclusively on human blood several times a day.
Behavior Patterns
They are wingless and cannot jump or fly; they move by crawling. Females lay eggs (nits) glued to the base of hair shafts. They survive only 1–2 days away from a human host.
Risks & Benefits
Risks include intense itching (pruritus) due to an allergic reaction to saliva, and potential secondary skin infections from scratching. They do not transmit diseases. There are no ecological benefits to humans.
Identified on: 4/4/2026