Your headlice questions answered

They feed on human blood, leaving tiny red spots that itch intensely. The female lays a daily batch of eggs (nits) which are attached to hairs close to the scalp. They hatch in about seven days and can live up to several weeks.

You can catch headlice if your hair touches the hair of someone who already has them. But as they move slowly contact needs to occur for about half a minute – they cannot jump, fly or swim, but walk from one hair to another.

No. Headlice affect only humans and cannot be passed onto or caught from animals.

Headlice are common in schoolchildren, particularly between the ages of four and 11, but anyone with hair can catch them (and parents often do!).

They don’t mind whether your hair is clean or not. It is a misconception that headlice infestation is as a result of dirty hair and poor hygiene. In fact clean, grease-free hair is easier for lice to cling on to. They can be found in all hair types, long or short, and in hair of any condition.

There are a number of chemical treatments that can work well but headlice are increasingly becoming resistant to them, so repeated treatment is frequently necessary. You shouldn't use treatments unless you know for certain that you have lice.

Sometimes complementary therapy treatments such as tea tree oil are recommended for treating headlice, but their effectiveness has not yet been proven.

You might wish to try removing the lice with a special comb. After washing the hair apply conditioner liberally. Comb the hair through with a normal comb first, and then a fine tooth nit comb. Comb from the roots along the complete length of the hair and after each stroke check the comb for lice and wipe it clean. Work methodically over the whole head for at least 30 minutes and then rinse the hair as normal. You should repeat every three days for at least two weeks.

Because of their size, re-infestation rate, life cycle, and their ability to develop immunity to insecticides. Lice can be a persistent and recurring nuisance, so it is important to treat them quickly and thoroughly.

You should always ask for advice before using medicated lotions on young babies (under six months), pregnant women or people with asthma, or allergies, and always read the instructions carefully.

No – having headlice is not a public health threat.