Life cycle of head lice
Head lice are parasitic insects that feed on human blood. Because they do not tolerate lack of food, they live by feeding continuously (similar to mosquitoes). Lice prefer certain people more than others depending on the composition of their blood
It takes 33 to 35 days from the time that the egg is deposited on the root of the hair until the louse dies. This is the life of a head louse. Brief but annoying. Their life cycle can be summed up as follows:
• Day 0 – The egg is laid on the root of the hair (nit).
• Day 6-7 – The louse hatches (larva).
• Day 8 to 17.- It moults successively (3 times) until, after the third, it becomes either male or female.
• Day 17 to 19.- It feeds and breeds. During this period the female lays its first egg, which occurs no more than one day after mating.
• Day 19 to 35.- The male continues mating with any female it meets and the females continuously lay eggs. Throughout its relatively short life it can lay up to 170 eggs.
Who can be infested?
Head louse infestation is most common in children aged 3 to 11 who go to preschool care centres, primary schools and household members of infested children. This age range is by no way exclusive because any human being provides the conditions necessary for their existence.
Head lice crawl, they cannot jump or fly, and they spread by direct contact with an infested person’s hair. Anyone in close contact with the head of another person who already has head lice is at greatest risk.
Signs and symptoms of infestation
• Tickling sensation of something moving around in the hair.
• Itching, caused by an allergic reaction to louse bites.
• Irritability and difficulty sleeping; head lice are most active in the dark.
• Sores on the head caused by scratching. These sores can sometimes become infected by bacteria present on the person’s skin.