In how many days do lice reproduce? - briefly
Head lice reach sexual maturity about 9–12 days after hatching, and females start laying eggs roughly a week later, so a full generation is completed in about two weeks. Consequently, the population can double within 14 days under optimal conditions.
In how many days do lice reproduce? - in detail
Lice complete their reproductive cycle in roughly one month under typical indoor conditions.
The cycle consists of three distinct phases:
- Egg (nit) stage – incubation lasts 7 to 10 days before hatching.
- Nymph stage – three molts occur over 9 to 12 days, after which the insect reaches adult size.
- Adult stage – females become sexually mature within 24 hours of the final molt and begin laying eggs. An adult female can produce 5 to 10 eggs daily, continuing for about 20 to 30 days before dying.
Key factors influencing the timeline include ambient temperature (optimal range 30 °C ± 2 °C), humidity (50 %–70 % relative), and host grooming frequency. Warmer environments accelerate development, potentially reducing the egg‑to‑adult interval to 12 days, while cooler or dryer conditions may extend it to 18 days.
Overall, from oviposition to the emergence of a new fertile adult, the process typically spans 16 to 22 days, after which the adult generation can generate a second generation within another 20 to 30 days, resulting in a population doubling roughly every month.