Human Head Louse

Natural Habitat

Exclusively on the human scalp and hair.

Diet & Feeding

Human blood (obligate hematophagous parasite)

Behavior Patterns

Head lice spend their entire life cycle on the human scalp, feeding on blood. They spread primarily through direct head-to-head contact. Nits (eggs) are laid on hair shafts close to the scalp and hatch in about 7-10 days. Nymphs mature into adults in about another 7-10 days. Adults live for about 3-4 weeks. They are largely inactive off a host.

Risks & Benefits

Potential risks include intense itching, skin irritation, and secondary bacterial infections from scratching. Despite common misconceptions, head lice are not known to transmit diseases to humans. They do not offer significant benefits to the ecosystem.

Identified on: 8/27/2025