The Three Stages of the Life Cycle:
- The nit (egg) is laid on the hair shaft. At first it is microscopic, but it enlarges and becomes tan in colour over 6-9 days.
- The nymph hatches from the egg and immediately begins to feed on blood. It is initially microscopic, but enlarges and becomes darker in colour as it ingests blood. Over 7-10 days, it gradually gets larger, moulting three times.
- The third time the louse moults it emerges as an adult and is capable of reproduction. It is also more able to transmit to others. The louse continues to live on the head for another 14-16 days. The fertilized female lays 8-10 eggs per day.