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Home Newsroom Head lice are getting harder to kill. Here’s how to break the nit cycle

Head lice are getting harder to kill. Here’s how to break the nit cycle

Media Contact
3rd March, 2025

Wrangling head lice, and the children they infest, must be up there with the most challenging duties a parent or carer has to face. And the job is getting harder.

Com­mon­ly used chem­i­cal prod­ucts aren’t work­ing as well as they once did, mean­ing head lice are hard­er to kill.

You can still rid your chil­dren of lice – but it’s like­ly to take some patience and persistence.

Remind me, what are head lice? And nits?

Head lice are tiny six-legged insects that are only found in the hair on a human’s head – most com­mon­ly in the hair of pri­ma­ry school-aged children.

Head lice have been a con­stant com­pan­ion for humans through­out their mil­lions of years of evolution.

Lice love liv­ing in our hair. But they scoot down to our scalp up to a half dozen times a day to drink our blood.

Their claws are per­fect­ly designed to scut­tle up and down shafts of hair. But while they’re nim­ble on our hair, once they’re off, they don’t last long –they’re clum­sy, unco­or­di­nat­ed and die quickly.

The term “nits” actu­al­ly describes the eggs of head lice. They’re often the first sign of an infes­ta­tion. And with one louse lay­ing more than 100 in their month-long lifes­pan, there can be a lot of them.

file 20250226 32 h6at8z.jpg?ixlib=rb 4.1
Head lice live for around a month.
logika600/Shutterstock

Can they spread diseases?

No. Head lice are annoy­ing and their bites may cause skin reac­tions. But Aus­tralian health author­i­ties don’t con­sid­er lice a health risk. There is no evi­dence that head lice can spread pathogens that cause disease.

The stig­ma of head lice infes­ta­tions can be greater than any direct health con­se­quences for infest­ed children.

Why do my children always pick up lice?

From child care through to pri­ma­ry school, it’s like­ly your child has had a head lice infes­ta­tion at least once. One Aus­tralian study found the infes­ta­tion rate in Aus­tralian class­rooms ranged from no cas­es to 72% of chil­dren affected.

Girls are more like­ly to be car­ry head lice than boys. Long hair means it’s eas­i­er for the head lice to hitch a ride.

Children work in class
One study found that in some class­rooms, almost three in four chil­dren had head lice.
CDC/Unsplash

Head lice don’t jump or fly, they move from head to head via direct contact.

Head lice come home with your chil­dren because they spend time in close con­tact with oth­er chil­dren, hug­ging, play­ing or crowd­ing around books or screens. Any head-to-head con­tact is a path­way of infections.

Rules dif­fer slight­ly between states but in New South Wales and Queens­land, chil­dren don’t need to be kept home from school because of head lice.

How can I keep my home free of head lice?

Keep­ing the house clean and tidy won’t keep head lice away. They don’t care how clean your bed sheets and tow­els are, or how fre­quent­ly you vac­u­um car­pets and rugs.

There may be a risk of head lice trans­fer on shared pil­lows, but even that risk is low.

There’s no need to change the child’s or oth­er fam­i­ly member’s bed­ding when you find lice in a child’s hair. Research-based rec­om­men­da­tions from NSW Health are that “bed linen, hats, cloth­ing and fur­ni­ture do not har­bour or trans­mit lice or nits and that there is no ben­e­fit in wash­ing them as a treat­ment option”.

I’ve used nit solution. Why isn’t it working?

A wide range of prod­ucts are avail­able at your local phar­ma­cy to treat head lice. Australia’s Ther­a­peu­tic Goods Admin­is­tra­tion assess­es prod­ucts to ensure that they are both safe and effective.

The prob­lem is that most of these prod­ucts are insec­ti­cides that kill the lice on con­tact but may not kill the eggs.

Also, if treat­ments aren’t com­plet­ed as direct­ed on prod­uct labels, some head lice won’t be killed.

Head lice also seem to be fight­ing back against the chem­i­cals we’ve been using against them and it’s get­ting hard­er to clear chil­dren of infestations.

So how can you get rid of them?

Mum combs child's hair
You’ll need con­di­tion­er and a nit comb.
riopatuca/Shutterstock

Don’t expect any mir­a­cle cures but health author­i­ties in Aus­tralia gen­er­al­ly rec­om­mend the “con­di­tion­er and comb” or “wet comb” method. This means you phys­i­cal­ly remove the lice with­out the need for chem­i­cal applications.

There are three key steps:

  1. immo­bilise the lice by apply­ing hair con­di­tion­er to the child’s damp hair and leav­ing it there for around 20 minutes
  2. sys­tem­at­i­cal­ly comb through the hair using a fine toothed “lice comb”. The con­di­tion­er and lice can be wiped off on paper tow­els or tis­sues. Only adult lice will be col­lect­ed but don’t wor­ry, we’ll deal with the eggs later
  3. repeat the process twice, about a week apart, to break the life cycle of the head lice.

Repeat­ing the process after a week allows the remain­ing eggs to hatch. It sounds counter-intu­itive but by let­ting them hatch, the young lice are eas­i­er to remove than the eggs. You just need to remove them before they start lay­ing a fresh batch of eggs and the infes­ta­tion continues.

While chil­dren are much more like­ly to have head lice, the real­i­ty is that every­one in the house­hold is just as like­ly to host a head louse or two. You don’t nec­es­sar­i­ly need every­one to have a treat­ment but “grown ups” should be on the look­out for lice too.The Conversation

Cameron Webb, Clin­i­cal Asso­ciate Pro­fes­sor and Prin­ci­pal Hos­pi­tal Sci­en­tist at NSW Health Pathol­o­gy and Uni­ver­si­ty of Sydney

This arti­cle is repub­lished from The Con­ver­sa­tion under a Cre­ative Com­mons license. Read the orig­i­nal arti­cle.

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