Head Louse
Scientific Name: Pediculus humanus capitis
Order & Family: Order: Psocodea (formerly Phthiraptera), Family: Pediculidae
Size: 2 to 3 mm in length (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
Strictly hematophagous; they feed 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) firmly glued to hair shafts. They cannot survive for more than 24-48 hours away from a human host.
Risks & Benefits
They cause intense itching (pruritus) and scalp irritation due to an allergic reaction to their saliva. While a nuisance and highly contagious through direct head-to-head contact, they are not known to transmit diseases. Benefit: None to humans or the ecosystem.
Identified on: 3/7/2026