Head lice are tiny grey and brown insects that cling to hairs but stay close to scalp where they feed. Nits are the empty egg cases of the lice after they have hatched and look like dandruff but stick to the hair.
Symptoms
Most people with lice have no symptoms except for occasional itchy scalp
Cause
Direct infection from another person who has lice. Head lice cannot jump or fly so they must walk from the hair of one person to the hair of another.
Treatment
Dimeticone lotion (an insecticide)
Wet combing with a nit or head lice comb (the fine comb traps and removes lice and nits through action of combing)
Isopropy myristate and cyclomethicone solution (an insecticide)
Coconut, anise and ylang ylang spray (a natural insecticide)
Malathion liquid (a chemical insecticide)
Prevention
Prevention cannot be guaranteed by any means but good hair hygiene will help reduce the frequency of infections. Detecting any infections and treating them straight away is the best way of dealing with the problem.