How do lice begin? - briefly
Lice start when a fertilized female deposits eggs (nits) on a host’s hair or clothing, which hatch after a few days. The emerging nymphs feed on the host’s blood and mature into adults within about a week.
How do lice begin? - in detail
Lice infestations start when a female adult deposits her eggs, called nits, on a host’s hair shafts close to the scalp. Each egg is secured with a cement-like substance that prevents it from falling off. After about seven to ten days, the egg hatches, releasing a nymph that resembles a miniature adult. Nymphs molt three times over a period of roughly ten days before reaching reproductive maturity.
Transmission occurs primarily through direct head‑to‑head contact. Sharing personal items such as combs, hats, helmets, or hair accessories can also transfer viable eggs or live insects. Lice do not survive long off a human host; they die within 24‑48 hours without a blood meal.
Factors that facilitate establishment include warm, humid conditions and dense hair that provides a stable environment for eggs and nymphs. Frequent close contact in schools, camps, or households increases the likelihood of spread. Poor hygiene does not cause lice, but infrequent hair washing may reduce detection of early infestations.
The reproductive capacity of a mature female is high; she can lay 5‑10 eggs per day, producing up to 100 eggs over her lifespan of about 30 days. This rapid increase explains why infestations can grow from a few individuals to dozens within weeks if left untreated.
Effective control measures focus on early detection, removal of eggs with a fine-toothed comb, and application of approved topical treatments that target both adults and nymphs. Re‑inspection after 7‑10 days ensures that any newly hatched nymphs are eliminated before they become reproductive adults.