3 days later, nymph sheds it's skin for the first time. Nymph's age is now approx 9 days old.
3 days later, nymph sheds it's skin for the second time. Nymph's age is now 12 days old
3 days later, nymph sheds it's skin for the third and last time. Nymph's age is now 15 days old. At this stage of it's life, it is now a mature and sexually active adult. Mating can occur 10 hours after reaching maturity, during which time they will mate frequently, several times each day.
Between 16-18 days old, the female will lay the first of her eggs.
18-34 days old the female will continue to fornicate and lay approx 4-6 eggs each day
35-40 days old. Since beginning life as an egg, the head louse eventually dies.
This analysis is based on one head louse, laying one egg, and progressing through the life cycle. Multiply that by 10 head louse or even more, each laying 4-6 eggs at one time, and progressing through to the end of it's cycle! Scary Stuff, isn't it?