Head lice reproduce asexually, with the female louse laying up to six eggs per day. These eggs are glued onto the hair shaft by the female’s secretions. They hatch into nits and take about a week to develop into adult lice. Once they have matured, they must be separated, which can take up to half an hour.
The life cycle of lice varies, depending on the bug. An adult female louse lays three to eight eggs per day and will live for up to 30 days on the head. The female will lay an average of 125 eggs during its lifetime. Ahead lice are most often spread through direct hair-to-hair contact. However, this is not necessarily caused by poor hygiene.
Lice cannot live without a human host. They need the warmth of the scalp for incubation and nourishment once they hatch. Once they are dislodged from the hair shaft, they will die or remain dormant. This means that they cannot live on bedding surfaces or other objects. Similarly, they cannot survive on pets or animals.
It has been hypothesized that some insects may reproduce in a sexual manner. However, this theory has not been confirmed. Several researchers believe that the sexuality of head lice is asexual. In fact, studies of the insecticide resistance of human lice have found that some species reproduce using alternative genetic systems. For example, the human ectoparasite, Pediculus humanus, reproduces through paternal genome elimination, which is a novel genetic system in insects. Moreover, males usually transmit maternally derived chromosomes to their offspring.