How many days after lice appear do they lay eggs? - briefly
Female head lice typically begin laying eggs about five to seven days after they hatch, and they continue to deposit one to three nits each day for several weeks. This reproductive schedule allows a rapid increase in infestation if untreated.
How many days after lice appear do they lay eggs? - in detail
Pediculus humanus capitis, the head louse, reaches reproductive maturity within a short period after the first nymphal stage appears. The egg‑laying phase begins roughly three to five days after a newly hatched nymph begins feeding on the host. During this interval, the insect undergoes two molts, transforming from a first‑instar nymph to a mature adult capable of oviposition.
Key points of the reproductive timeline:
- Incubation of eggs (nits): 7–10 days at typical indoor temperatures (20–25 °C).
- Nymph development: Each molt lasts about 1–2 days; after the second molt, the adult emerges.
- Onset of egg production: The adult starts depositing eggs approximately 48–72 hours after its final molt, continuing for several weeks.
Females can lay 4–6 eggs per day, with a total clutch size ranging from 30 to 50 eggs over her lifespan. Egg laying persists as long as the adult has access to a blood meal and favorable environmental conditions. Consequently, the period from the first visible louse to the commencement of oviposition is typically three to five days, after which the population can expand rapidly if untreated.