From what do lice emerge? - briefly
Lice develop inside eggs, known as nits, that are firmly attached to hair shafts. When development is complete, the nymphs hatch and emerge onto the host.
From what do lice emerge? - in detail
Lice originate from eggs laid by adult females on the host’s hair or feathers. The eggs, commonly called nits, adhere firmly to each strand by a cement‑like secretion. After an incubation period of 6‑10 days (depending on species and temperature), the nymphs hatch and begin feeding on the host’s blood. They undergo three successive molts, each lasting several days, before reaching reproductive maturity.
Key points of the infestation cycle:
- Egg deposition: Female lays 5‑8 eggs per day, attaching them within 1 mm of the scalp or skin surface.
- Hatching: Nymph emerges, initially translucent, becoming pigmented after the first molt.
- Development: Three molts occur over 9‑12 days; each stage requires a blood meal.
- Reproduction: Mature adult lives 30‑40 days, producing up to 150 eggs in its lifespan.
Transmission occurs through direct head‑to‑head or body contact, sharing of personal items (combs, hats, bedding), and, for certain species, infestation of animals that serve as reservoirs (e.g., dogs, cats, livestock). Environmental survival is limited; lice cannot live more than 24‑48 hours off a host. Consequently, the primary source of a new infestation is contact with an already infested individual or contaminated personal objects that still bear viable eggs.