How to spot headlice

What are headlice?

Lice are small, flat insects about 2mm to 3mm long that breed all year round. They live on the hair and come down to the scalp to feed and lay eggs. They feed on blood by sticking their tube-like mouthparts into your scalp several times a day.

Lice can't jump, fly or swim. They crawl very quickly from hair to hair and hold on with their claws. Lice can travel from one head to another when the two come very close together. Those found off the head are usually sick, old or injured and do not lay eggs.

Lice can live underwater - they stay on the head and don't die if you swim or shower.

Female lice lay about seven to 10 eggs each day. Eggs are laid close to the scalp with each egg firmly glued to a hair. Eggs hatch in around seven days (the empty egg case is technically the "nit" but many people call all eggs "nits"). A louse will live for up to 40 days.

Signs of headlice

Frequent itching is a sign of lice, but it's surprisingly unreliable. According to some studies, only about 30 percent of infected children get itchy. And almost as many kids scratch their heads when they don't have lice. If there are lice at your children's school or pre-school, check their heads regularly.

Eggs are not difficult to see: use a strong light and look at the hair. Newly laid eggs can be found within about 1.5cm of the scalp, while older eggs that have hatched sit further away from the scalp. The egg - or nit - is glued to each hair and take about seven to 10 days to hatch. Eggs will feel sandy or gritty when fingers are run through the hair. While there may seem to be a lot of eggs, only about a dozen lice at the most will be active at the time.

Live lice move quickly and are difficult to see, but small red dots behind the ears and on the nape of the neck may be headlice bites. Lice are usually between 2 to 4mm long and about 1mm wide. They have six legs with claws and are usually light or dark brown in colour depending on the child's hair colour (which they mimic).