How long does it take from nits to become lice? - briefly
Nits develop into mobile lice in roughly 7–10 days, typically about nine days under normal temperature and humidity. Environmental factors such as temperature and moisture can shift this period slightly, but the standard incubation window remains within that range.
How long does it take from nits to become lice? - in detail
Nits hatch into first‑instar nymphs after an incubation period that typically ranges from 7 to 10 days, depending on ambient temperature. At 30 °C (86 °F) the cycle shortens to about 7 days; cooler conditions extend it proportionally.
The newly emerged nymph undergoes three successive molts before reaching reproductive maturity:
- First molt: 2–3 days after hatching.
- Second molt: another 2–3 days later.
- Third molt: an additional 2–3 days.
Each stage requires a blood meal to trigger the molt. Summed together, the three nymphal phases add approximately 6 to 9 days.
Consequently, the complete development from egg to adult louse generally spans 13 to 19 days, with the most common range being 10–14 days under typical household conditions. Variations arise from temperature fluctuations, humidity levels, and the host’s grooming practices. Faster development occurs in warm, humid environments; lower temperatures can delay hatching and molting, extending the total period.