How long does a louse take to lay a nit? - briefly
A mature female head louse usually lays a «nit» within 24–48 hours, producing about five to six eggs per day.
How long does a louse take to lay a nit? - in detail
The adult female head louse deposits a single egg, called a nit, roughly every 24 hours under optimal conditions. Egg‑laying begins three days after the female reaches maturity, and continues until death, typically after 30 days of adult life.
Key factors influencing the oviposition interval:
- Ambient temperature: 29–32 °C accelerates metabolism, maintaining the one‑day cycle; lower temperatures lengthen the period up to 48 hours.
- Host grooming: mechanical removal of nits reduces the number of viable eggs, but does not alter the female’s internal rhythm.
- Nutritional status of the host: adequate blood intake sustains the female’s reproductive output; severe anemia can extend the interval.
The developmental timeline of the egg is as follows:
- Deposition (day 0). The female secures the nit to a hair shaft with cement.
- Incubation (days 0–7). At 30 °C, hatching occurs after 6–7 days; cooler environments delay emergence proportionally.
- Hatching (day 7). The newly emerged nymph begins feeding immediately.
Thus, under typical indoor conditions, a mature female louse lays one nit per day, with each nit requiring approximately one week to hatch. Adjustments in temperature or host condition modify both the laying frequency and incubation period within the ranges specified above.