Head Lice Facts




Headlice can jump or swim from person to person.

 NO!  Headlice have legs designed for climbing so need to be able to crawl from person to person in close proximity. Headlice cannot swim.

Only dirty people have headlice.

 NO! Headlice feed on blood, not dirt. Anyone can host headlice and they are comfortable living in any suburb.

People with dark-coloured hair get headlice more than other people.

 NO! It is easier to see the yellow-white nits in dark hair so darkhaired people may be able to manage the problem more easily. People with light-coloured hair may find it is easier to manage the brown headlice. Headlice like hosts with hair of any colour.

Headlice prefer certain blood types.

 NO! Headlice like to feed on any blood.

Children get headlice from classroom carpets or animals.

 NO! Headlice only live on human heads.

Schools with policies on headlice don’t have children with headlice.

 NO! A policy is not a magic protection but a well-thought-out policy does help a school manage the problem. But, a policy no-one follows is no help at all.


Nits and Head lice... What to look for

Head Lice are small insects approximately 2mm to 4mm long and about 1mm wide. They have six legs with claws and are usually a light or dark brown colour.

Nits (Head Lice eggs) are small and hard like a grain of salt and are yellow-white in colour. Nits are usually found on the hair very close to the scalp. Those found further than 1-1.5cm from the scalp are probably dead or hatched.

Sometimes a person with Head Lice or Nits might feel itchy, but not always.

Checking for Headlice or eggs

Check weekly using bright light and by parting the hair. Check the scalp, especially at the front, nape of the neck, behind the ears and at the base of a pony tail or plaits.

Small red dots behind the ears and on the nape of the neck may be headlice bites. Eggs are usually easier to see than headlice. Don’t be confused by dandruff that is flaky and easily removed. Eggs will feel sandy or gritty when fingers are run through the hair.

Transmission of Head Lice and Nits

Head Lice crawl from head to head. Because young children are often in close proximity to one another in play or classwork, or with family adults at home, head lice have opportunities to move from one head to another. It is impossible to know the origin of an outbreak.

A less likely method of transmission is through sharing things like combs, hairbrushes, hats, and other things that touch the head and hair.

Because Head Lice need food, humidity and warmth to survive it is unlikely they will be found alive on car seats, curtains or carpets.

Adolescents and adults tend to spend little time in close proximity to others so transmission of Head Lice amongst older people is less likely than amongst the young.

Temperature and Humidity for Lice and Nits

Headlice and the eggs (nits) enjoy warmth. Between 28oC and 32oC

makes the human head an ideal place for headlice to live. Humidity needs to be about 75% in order for eggs (nits) to hatch.

Nit and Head Lice Food

Blood is the food of Head Lice. Headlice need something to cling to and to lay their eggs on. Headlice find a head of hair a most suitable place to live.

Lifecyle of Nits and Head Lice














A female louse will lay approximately 7 to 10 eggs (nits) per day in the hair, within 1.5cm of the scalp; these eggs resemble dandruff but cannot be brushed off.

Egg is laid on the hair shaft; an egg is called a 'nit'.

Nymph (baby louse) emerges after 6 days.

Once hatched, the bug moults three times in its life cycle, shedding the hard shell to grow.

Emerging from their third moult as adult headlice, the female and slightly smaller male begin to reproduce.

Female lays first egg 1 or 2 days after mating.

Females can lay approximately 100 eggs in her lifetime.

The life span of a louse is approximately 30 to 35 days.


Hosting headlice

Headlice do not cause disease. They may cause an uncomfortable itching. At worst, a child with headlice may scratch excessively and break the scalp possibly allowing infection in. An infestation of headlice should be detected and dealt with long before it becomes either highly visible or irritating.

Preventing headlice

  • Avoid head to head contact.
  • Don’t share brushes, combs, hats and other items that come into contact with hair.
  • Discourage children from playing with each others’ hair.
  • Tie long hair back or plait it.
  • Brush hair regularly.
  • Check the hair of everyone in the family at least once a week.
  • Take action if a child is scratching unusually – check their head carefully.

Treatment of Head Lice and Nits

Ideally, once headlice are detected in a school, the whole school community should take action at the same time and over a period of weeks. One untreated head in a community can ensure an outbreak continues for months. Treatment must be thorough, regular and carried out over a period of weeks by everyone. Even so, such treatment will not prevent a re-infestation originating from another community. Keeping headlice under control requires constant vigilance. Effective treatment usually requires a combination of methods to be most successful.

Dry combing

This method is for removal of headlice and eggs.

Use a metal fine-toothed comb.

Fingernails can effectively remove eggs.

Individual strands of hair can be cut to remove difficult eggs.

Some combs will only extract adult headlice, leaving behind the eggs (nits) and smaller lice; the closer together the teeth of the comb are, the more successful combing will be.

Wet combing

This method, using any kind of hair conditioner, is for detection and removal of headlice and eggs. It is recommended that this treatment be repeated on alternate days for three weeks. The idea is to smother the headlice with conditioner, preventing them moving away, and to allow manual removal. Do not use conditioner within a day of using a chemical treatment; it will make the chemical treatment ineffective.

Apply enough conditioner (much more than usual) on dry hair to thoroughly cover the whole scalp and all the hair from the roots to the tips.

Keep conditioner in the hair.  Conditioner stuns the insects for about 20 minutes.

Comb the hair straight and get knots out with an ordinary comb.

Use a fine-toothed comb to systematically comb the hair.  Comb the full length of each hair.

Wipe the comb with a clean tissue after each stroke of the comb.

After thorough combing and inspection, wash the conditioner out.

Electric combs

Electric battery operated combs are available to be used on dry hair. These claim to stun or kill the headlice so they let go of the hair and can be combed out. Clean the teeth after each stroke of the comb. Electric combs should be used on alternate days for two or three weeks to break the breeding cycle. People with epilepsy, heart disease or pacemakers should not use them.

Hair Cuts

Short hair is easier to comb, requires less time to treat and makes detection easier. It should not be necessary to shave heads. Hairdressers may refuse to cut infested hair.


The use of any chemical in or on the body carries risk. Some older treatments for headlice are no longer available because of the risk they posed. The chemicals used are insecticides and should be used with care and strictly as directed by the manufacturer. Chemicals are expensive.

There are three chemicals that are most commonly used:
Pyrethrins – derived from chrysanthemum flowers, these attack the insects’ nervous system but break down in sunlight. These are usually combined with piperonyl butoxide for more effectiveness.
Pyrethroids – synthetic pyrethrins that are more stable in sunlight.
Maldeson – an organophosphate insecticide that attacks the insects’ nervous system.

  • Apply the treatment strictly in accordance with the manufacturer’s instructions.
  • Treat those members of the household who appear to be hosting headlice. Do not treat babies with chemicals.
  • Do not wash the hair or use conditioners for at least 24 hours after treating. Treatments are designed to coat the hair shaft and should be allowed to remain. Do not wash chemicals off.
  • Do not use hairdryers on treated hair. The heat may break down the active chemical.
  • Comb the hair carefully to remove as many dead or live headlice and eggs as possible.
  • Repeat the treatment after seven to ten days.
  • Check all members of the household daily for a period of three weeks.

Herbal remedies

Several herbal preparations are available, however the effectiveness of these is not clearly established. Most herbal remedies might be regarded as expensive conditioners that are no more effective than other conditioners. Some, such as tea tree oil, may be, volume for volume, more toxic to humans than chemical preparations. Olive oil, hair gel and mayonnaise may make combing easier.

What else can help?

Washing all bed linen and certainly pillowcases and towels in hot water (at least 60 degrees centigrade) and tumble drying for 20 minutes on high. Other items that have come in contact with heads should also be thoroughly cleaned. Soak hairbrushes and combs in hot water for at least 20 minutes. Vacuuming carpets and rugs may also be helpful, if only to ensure that dead nits and lice are collected and not left to reappear on the heads or clothing of anyone in the household.