After how long are lice born? - briefly
Lice eggs typically hatch within 7–10 days, and the emerging nymphs reach adulthood after an additional 7–10 days.
After how long are lice born? - in detail
Lice develop from eggs (nits) to mature insects through a well‑defined cycle. An adult female attaches about 6–10 eggs to each hair shaft, cementing them near the scalp. The incubation period for these eggs averages 7–10 days at typical human body temperature (≈37 °C). During this time the embryo matures inside the shell, consuming the yolk supply.
Once the nits hatch, the emerging nymph resembles a small adult but lacks full reproductive capability. Nymphal development proceeds through three successive molts. Each molt requires roughly 2–3 days, resulting in a total nymphal phase of about 6–9 days. After the final molt, the lice reach adulthood and become capable of laying eggs.
Consequently, the complete interval from egg deposition to a reproducing adult ranges from 13 to 19 days, depending on environmental conditions such as temperature and host hygiene. Under optimal conditions (warm, moist scalp), the cycle shortens toward the lower end of this range, while cooler or drier environments can extend it slightly.
Key timing points:
- Egg incubation: 7–10 days
- Each nymphal instar: 2–3 days (three instars)
- Total time to reproductive adult: 13–19 days
Understanding these intervals explains why infestations can expand rapidly; a single adult female can produce 5–6 eggs per day, and new adults appear within three weeks of the initial infestation.