How many eggs do lice lay per day? - briefly
A female head louse usually deposits about five eggs per day, accumulating roughly 100 eggs over her lifetime.
How many eggs do lice lay per day? - in detail
Lice reproduce quickly, but the daily egg output varies among species.
- Head lice (Pediculus humanus capitis): a mature female deposits 5–7 eggs each day. Over her lifespan of about 30 days, she can lay roughly 100–150 eggs.
- Body lice (Pediculus humanus humanus): a female lays 4–6 eggs daily, accumulating 80–120 eggs before death.
- Pubic lice (Pthirus pubis): a female produces 1–2 eggs per day, resulting in 20–30 eggs total.
Eggs, called nits, are attached to hair shafts within 1 mm of the scalp or body hair. The incubation period lasts 7–10 days at typical human body temperature; the nymph emerges and matures to reproductive age in another 7–10 days. Factors that influence egg production include temperature, host hygiene, and the health of the adult female. Warmer conditions and well‑nourished females tend to increase daily output, while cold environments and nutritional stress reduce it.
Overall, a single adult female lice can generate enough eggs to sustain an infestation within a week, underscoring the rapid population growth potential of these ectoparasites.