How often do lice lay eggs? - briefly
Female head lice lay eggs roughly every 24–48 hours, depositing about five to six nits each time. This oviposition continues for approximately three to four weeks.
How often do lice lay eggs? - in detail
Lice reproduce by depositing tiny, oval eggs called nits on hair shafts or clothing fibers. A female adult typically lays a new nit every 3–5 hours, which translates to roughly 4–8 eggs per day. Over her lifespan of about 30 days, a single louse can produce 100–150 nits, assuming optimal conditions.
The rate of oviposition depends on species, temperature, and host availability. Human head‑lice (Pediculus humanus capitis) operate most efficiently at 30–32 °C; at lower temperatures the interval between successive eggs lengthens to 6–8 hours. Body‑lice (Pediculus humanus corporis) exhibit a similar pattern but may lay slightly fewer eggs per day because they feed less frequently.
Egg development proceeds independently of the laying schedule. After being attached, a nit requires 7–10 days to hatch, the duration shortening with higher ambient temperatures. The continuous laying of eggs ensures overlapping generations: while older nits are nearing emergence, newly deposited ones begin their incubation.
Key points summarizing the reproductive rhythm:
- Egg deposition interval: 3–5 hours per nit (≈4–8 per day).
- Total output per female: 100–150 nits over ~30 days.
- Temperature influence: optimal 30–32 °C yields fastest laying; cooler conditions extend intervals.
- Species variation: head‑lice and body‑lice have comparable rates, with minor differences in daily totals.
Understanding this pattern clarifies why infestations can expand rapidly: each adult contributes dozens of viable eggs within a week, sustaining a growing population if untreated.