Head lice are small insects that live and feed on the human scalp, and lay eggs (nits) on the hair and around the roots of the person carrying them. They have been around for thousands of years and given the chance will move from head to head without discrimination. They are not dangerous, do not carry or transmit disease, and are not a sign of poor hygiene.




Head lice are spread from direct head-to-head contact with another person who has head lice. Contrary to popular belief, head lice are wingless and lack the leg structure to adequately leap large distances, so they cannot fly or jump from head to head. They are only physically capable of crawling. This can happen when people play, cuddle or work closely together. Head lice are most common among children and their families. If your family has head lice, tell anyone who has head-to-head contact with them, so that they can check and treat their family if needed. There is no need to treat the whole family, unless they also have head lice. Head lice breed at a ferocious rate – the female louse will lay between three and eight eggs per day in the hair of the host, usually within 1.5cm of the scalp.




The scalp may itch as the skin reacts to the saliva of the head lice. However, itchiness can take weeks to develop, and if you have had head lice more than once the skin may become desensitised and there may be little or not itch.


Crawling head lice may be seen in the hair, but head lice can be hard to spot because they move quickly. Head lice can move at 30cm per minute and can be difficult to spot. Adult lice are usually dark brown and about 2-3mm long. Hatchlings (young lice) are a lighter brown and about 1-2mm long. Eggs (nits) may be seen attached to the hair shaft but they may be very tiny and hard to see, especially newly laid eggs close to the scalp. They are grey-white and about the size of a grain of salt.


The easiest and most effective way to find head lice is to follow these steps weekly:


Step 1: Using a fine-tooth comb, comb hair conditioner on to dry, brushed (detangled) hair. This stuns the hair making them lose their grip on the hair stands.
Step 2: Wipe the conditioner from the comb onto a paper towel or tissue.
Step 3: Look on the tissue and on the comb for lice and eggs.
Step 4: Repeat the combing for every part of the head at least four or five times.
Step 5: If the person has been treated recently and only hatched eggs are found, you may not have to treat them again since the eggs could be from the old infection.
Step 6: If lice or eggs are found, the person should be treated.




* Check your child’s hair regularly for head lice and eggs as described above  

* Tie long hair back – braid and/or put up if possible  

* Consider applying hair gel or mousse – these do not prevent or repel head live but may help keep stray hair strands from contact with other heads  

* Avoid sharing combs or brushes  

* Immerse brushes and combs in hot water for 10 minutes after use to kill any head lice or eggs trapped in them  

* Remind your child to avoid head-to-head contact with other children e.g. when working at the computer with others, playing or hugging.




Head lice and eggs do not survive ling away from the human scalp, as they are human parasites. It is not necessary to wash all the household linen or clothing, to vacuum, scrub or spray the house with insecticide. Pillow slips and towels may be soiled with head lice debris including droppings and moulted lice skins, so they should be washed on the first day of treatment.




The two main options that are available for treating head lice are the ‘Conditioner and comb’ method and the use of an insecticide.


Insecticide Products:


There are three groups of insecticides: Organophosphates (such as maldison and malathion), pyrethrins and synthetic pyrethroids (such as permethrin and bioallethrin).


No insecticide is guaranteed to kill all eggs. Eggs which are not killed or removed manually will hatch 7-10 days after being laid. The hatchlings should be combed out daily using hair conditioner as they may be transferred to other children. Hatchlings will mature about one week and start laying more eggs, continuing the cycle. If insecticide is used, treatment should be applied on Day 1, Day 7 and Day 14 to kill any hatchlings before they mature and lay more eggs. However, if the hair is combed daily with hair conditioner for 10 days to remove the hatchlings, then the second and third insecticide treatments can be omitted. To prevent skin irritation, do not repeat insecticide treatment more than 3 times, one week apart.


Head lice that are resistant to an insecticide will still be alive the 30 minutes after the insecticide treatment, if the insecticide was properly applied. If this happens, thoroughly wash out the first insecticide and re-treat the hair the same day with another type of insecticide (i.e permethrin, pyrethrin or malathion), not a different brand of the same type of insecticide.


Insecticide treatments may not be suitable if you are pregnant or breastfeeding, in children less than 12 months old, in people who have insecticide allergies, very sensitive skin, open wounds on the scalp or asthma. People who cannot use insecticides should use the ‘Comb and Conditioner’ Treatment instead.


Comb and Conditioner Treatment:


If you choose not to use insecticides, then the method described in ‘Finding Head Lice” for can be used to treat them, combing through conditioner every two days until there have been no new eggs or lice found for 10 days.


Generally, eggs will hatch 7-10 days after being laid on the hair shaft. The 10 day period is therefore recommended as the most effective time needed to break the reproductive cycle of the head lice. The reproductive cycle is broken by combing out the emerging hatchlings every 1-2 days before they mature enough to lay further eggs (about a week after hatching).