How many nits do lice hatch? - briefly
Each egg (nit) produces a single louse when it hatches.
How many nits do lice hatch? - in detail
Lice females typically lay between 5 and 10 eggs per oviposition, and a single adult can produce up to 50 eggs during its lifespan. Each egg, commonly called a nit, is affixed to hair shafts near the scalp with a cement‑like secretion. The hatching period ranges from 7 to 10 days at temperatures around 30 °C (86 °F); lower ambient temperatures extend incubation up to 14 days.
Factors influencing the number of viable nits that emerge include:
- Temperature: Optimal warmth accelerates embryogenesis; cooler conditions delay or reduce hatch rates.
- Humidity: Relative humidity above 50 % supports egg development; desiccation can cause embryonic mortality.
- Host grooming: Frequent combing or scratching removes eggs before they hatch, decreasing the effective yield.
- Egg viability: Approximately 80–90 % of laid eggs successfully hatch under ideal conditions; the remainder fail due to structural defects or environmental stress.
The life cycle proceeds as follows: egg → nymph (three molts) → adult. After hatching, a nymph requires about 9–12 days to reach sexual maturity, after which reproduction begins. Consequently, a single infestation can expand rapidly: an initial clutch of 5–10 nits can generate 6–8 mature adults within two weeks, each capable of laying another batch of eggs.
In summary, a mature female louse can deposit up to 50 eggs over her 30‑day lifespan, with each oviposition yielding 5‑10 nits, of which roughly 85 % hatch under optimal conditions. The total number of emerging nits depends on environmental temperature, humidity, and host behavior.