Head lice (Pediculus humanus capitis) are each about the size of a sesame seed, and can easily be seen, although they hide quickly when exposed to light. They are wingless, parasitic insects that live and feed on blood from the scalp.
Lice can't jump or fly, but crawl from head to head. The eggs of head lice (nits) can be seen as little white specks, glued to the scalp hairs.
Children are more inclined to get lice because they have frequent head-to-head contact, such as sharing secrets or when playing games or sport.
Contrary to popular belief, contracting lice is not related to poor hygiene - in fact, head lice are thought to prefer clean hair to dirty hair! However, good hygiene can combat body lice - a different variety, and seldom a problem in children.
If your child has lice, you have to notify the school.
Reviewed by Dr Rowan Dunkley, Paediatrian, Red Cross Children’s Hospital, Cape Town. February 2015.