How do lice get started? - briefly
Infestation starts when viable eggs are transferred to a new host through direct head contact or shared items such as combs, hats, or pillows. The eggs hatch within 7‑10 days, and the emerging nymphs mature into reproducing adults, completing the cycle.
How do lice get started? - in detail
Lice infestations begin when a gravid female deposits her eggs, called nits, on a host’s hair shaft close to the scalp. The eggs hatch in 7‑9 days, releasing nymphs that mature into adults within another 7‑10 days. An established population can develop in as little as two weeks.
Transmission occurs primarily through direct head‑to‑head contact, which transfers live insects or nits from one person to another. Secondary routes include sharing personal items that touch the scalp, such as combs, hats, helmets, hair accessories, and bedding. Lice cannot survive more than 24 hours off a host, so the risk from environmental surfaces is low but not negligible if the items remain moist and warm.
Factors that facilitate the initial colonization:
- Close physical interaction in schools, camps, or sports teams.
- Crowded living conditions where head contact is frequent.
- Inadequate personal hygiene practices that allow nits to remain undetected.
- Use of infrequently washed headgear or shared grooming tools.
Once the first adult female establishes herself on a new host, she begins laying 5‑6 eggs per day. The cycle repeats, producing a rapid increase in numbers if untreated. Early detection of nits near the scalp, combined with prompt removal and treatment, interrupts the process before the population reaches the reproductive threshold.