How many lice hatch from one egg? - briefly
Each louse egg, known as a nit, produces one nymph when it hatches. The emergence occurs after roughly 7–10 days, depending on ambient temperature.
How many lice hatch from one egg? - in detail
Lice reproduction relies on the deposition of individual eggs, commonly called nits, onto the host’s hair shaft. Each nit encloses a single embryo, and the developmental process culminates in the emergence of one juvenile louse.
Under optimal conditions—approximately 30 °C temperature and 70‑80 % relative humidity—hatching efficiency approaches 100 %. The incubation period ranges from 7 to 10 days, after which one nymph exits the egg. Deviations from these environmental parameters decrease the hatch rate; temperatures below 20 °C or humidity under 50 % can reduce emergence to 60‑70 %.
Factors influencing successful emergence include:
- Ambient temperature and humidity
- Host grooming frequency
- Application of insecticidal treatments
- Egg attachment strength to the hair shaft
A mature female typically deposits 5‑10 nits per day, accumulating up to 100 eggs over her lifespan. Consequently, each egg yields a single adult after successive molts (nymph → adult). The total number of lice generated by one egg is therefore one, provided the egg is not compromised by adverse conditions.