Head lice are small grey or brown insects. Adults measure 2-4mm (about the size of a sesame seed), and their eggs (nits) are smaller than a pinhead (about 1mm in length). Head lice have 6 legs and move by crawling.

Head lice like to live in a warm and humid environment so the females lay their eggs close to the scalp (about 1cm away). Lice and nits are often found behind the ears, along the hairline and at the nape of the neck because these areas are warm and dark.

Anyone can get head lice, but they are most common in children between 3-12 years of age. This may be because of close head contact between children. Girls seem to be more likely to get them than boys.

If an outbreak of head lice occurs at school, it is recommended that children are checked for head lice. If lice are detected, the affected children should be treated and the school and close contacts should be informed to prevent them spreading further. Children should also be encouraged not to share personal items (e.g. hair ties, scarves or brushes).

The most common symptom of head lice is an itchy scalp, although many head lice infestations cause no symptoms at all. That is why it is so important to actively check for head lice if anyone is suspected to have come into contact with an infestation.

Some people will have an allergic reaction to the bites, which can make the itching worse. Other possible symptoms include small red blotches on the scalp (from the biting as the head lice feed on human blood), the presence of nits or live lice, and the feeling of something moving in the hair.

As we have already seen, lice and nits are often found behind the ears or at the nape of the neck so these should be the areas that are checked first.

Bug busting : This involves combing the hair in a methodical fashion with a special comb
Insecticides : The use of these is declining as concern about resistance grows
Non-insecticides : These work by smothering the lice (with dimeticone) and, because the mode of action is physical not chemical, the lice are unable to build up any resistance to the product. Dimeticone is a noninsecticide.

The best way to detect head lice is by regularly checking the hair with a special nit comb - it is generally advised that parents check their children once a week. Such regular checking makes it easier to treat an infestation and reduces the chances of the lice being passed onto others.

Head lice can be removed through combing alone, however this takes a long time and can be an uncomfortable process. It is usually recommended that a specific product designed for the elimination of head lice and nits is used.

Dimeticone is generally regarded as the most effective ingredient in the treatment of head lice today, with treatment times as low as 10-15 minutes. Two treatments are required (to ensure that any newly hatched lice are also caught). the chances of the lice being passed onto others.

Head lice can be removed through combing alone, however this takes a long time and can be an uncomfortable process. It is usually recommended that a specific product designed for the elimination of head lice and nits is used.

Dimeticone is generally regarded as the most effective ingredient in the treatment of head lice today, with treatment times as low as 10-15 minutes. Two treatments are required (to ensure that any newly hatched lice are also caught).

Just before the end of winter term, 250 mums dropping off or collecting children from 10 different schools around the UK let off a head of steam about that most infectious of topics: head lice. The results may cause you to scratch your head in surprise... Click here to download