How do lice emerge? - briefly
Lice develop from eggs (nits) attached to hair shafts; after a 7‑10‑day incubation the eggs hatch and nymphs emerge, looking like tiny adults. These nymphs then molt three times before attaining full reproductive maturity.
How do lice emerge? - in detail
Lice develop from eggs that are firmly attached to hair shafts near the scalp. The female deposits each egg, called a nit, at an angle that secures it with a cement-like substance. Incubation lasts 7–10 days under typical indoor temperatures (20‑30 °C) and relative humidity above 50 %.
When the embryo reaches full maturity, enzymatic activity dissolves the cement, allowing the nymph to emerge. The newly hatched nymph resembles a miniature adult but lacks fully developed reproductive organs. It must feed on blood within a few hours to survive; failure to obtain a meal leads to rapid mortality.
The nymph undergoes three successive molts, each lasting 3–5 days, before attaining adult status. Molting is initiated by hormonal changes triggered by blood ingestion and ambient conditions. Adults are capable of reproduction after 5–7 days of maturation.
Key points of the emergence process:
- Egg attachment: cement secretion anchors each nit to the hair shaft.
- Incubation: 7–10 days, temperature and humidity dependent.
- Hatching: enzymatic breakdown of cement releases the nymph.
- Early feeding: immediate blood intake required for survival.
- Molting cycle: three stages, each requiring a blood meal.
- Adult maturation: reproductive capability achieved after approximately one week.
Understanding each stage clarifies how lice populations establish and expand on a host.