Head louse (Nymph/Adult)

Natural Habitat

Exclusively on the human scalp and hair, where they stay close to the skin for warmth and food.

Diet & Feeding

Obligate hematophagous parasites; they feed on human blood several times a day.

Behavior Patterns

They are wingless and cannot jump or fly; they move by crawling from hair to hair. Females lay eggs (nits) and cement them to the hair shaft near the scalp. They cannot survive for more than 24-48 hours off a human host.

Risks & Benefits

They do not spread disease but cause intense itching (pruritus) and scalp irritation due to an allergic reaction to their saliva. Secondary bacterial infections can occur from scratching.

Identified on: 2/15/2026