How many days do lice breed? - briefly
Female head lice deposit an egg roughly every 1‑2 days, and the complete development from egg to adult requires about 7‑10 days. Consequently, a new generation can appear within a week to ten days.
How many days do lice breed? - in detail
Lice complete their reproductive cycle within a relatively short period. An egg, commonly called a nit, requires approximately 7–10 days to hatch under typical indoor temperatures (20‑25 °C). After emerging, the nymph passes through three developmental stages, each lasting about 3–4 days. Consequently, the transition from egg to mature adult occupies roughly 14–21 days in total.
Female lice become fertile shortly after their final molt. Once fertilized, a female can lay 5–10 eggs per day, with a lifetime output of up to 300 eggs. Egg‑laying continues throughout the adult’s lifespan, which is about 30 days. The interval between successive oviposition events is generally 24–48 hours.
Key factors influencing the timeline:
- Temperature: Higher ambient temperatures accelerate egg incubation and nymph development; lower temperatures extend each phase.
- Host hygiene: Frequent washing or chemical treatments can reduce egg viability and increase mortality of early nymphs.
- Population density: Crowded infestations may lead to competition for feeding sites, slightly lengthening the maturation period.
Overall, the breeding window for a single generation spans roughly two to three weeks, after which the cycle repeats as newly emerged adults begin reproducing.