Head louse

Natural Habitat

Human scalp and hair

Diet & Feeding

Human blood (they are obligate parasites)

Behavior Patterns

Head lice spend their entire lives on the human scalp, feeding multiple times a day. They cannot fly or jump, and typically spread through direct head-to-head contact. Females lay eggs (nits) on hair shafts close to the scalp, which hatch in about 7-10 days. The nymphs mature into adults in about another week.

Risks & Benefits

Potential risks include intense itching, scalp irritation, secondary bacterial infections due to scratching, and sleep disturbance. They are primarily a nuisance and do not typically transmit diseases. There are no known benefits to humans or the ecosystem from head lice.

Identified on: 10/17/2025