1. Nits take about 1 week to hatch (range 6 to 9 days). Viable eggs are usually located within 6 mm of the scalp.
2. Once hatched, it takes 7 days for a nymph (pin size) to grow to an adult (sesame size) and lay eggs.
3. To live, adult lice need to feed on blood several times daily. Without blood meals, the louse will die within 1 to 2 days off the host.
4. Nits off heads die within a week. They can only live in a temperature consistent with a scalp (body temperature). Viable nits (nits capable of hatching live lice) must be attached within 6mm of scalp (half an inch).