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Head Lice in Schools


Head lice can be a problem in classrooms as they can spread from student to student. Learn more about identifying and dealing with head lice.

Head lice are tiny, wingless insects that live and breed in human hair. They move quickly when you part the hair and are hard to see. Newly-laid eggs are firmly glued to the hair and are found very close to the scalp.

Head lice eggs:

  • Are very small – about half the size of a pinhead
  • Are grey to brown in colour
  • Can take about 7-10 days to hatch

Head lice facts

  • Head lice have nothing to do with lack of cleanliness – anyone can get lice.
  • They are a nuisance, but they do not cause illness.
  • They are not a public health problem because they do not transmit disease.

Looking for head lice

  • Live head lice
    They can be difficult to see because greyish insects move quickly when hair is parted.
  • Head lice eggs
    Eggs are:
    • Pinhead in size
    • Colour of the scalp
    • Glued to the hair shaft less than ½ inch away from the scalp

    Note: Do not worry about eggs more than ½ inch from the scalp. These are empty white shells of eggs that have hatched and are not a problem.

  • Itchy scalp
    This might indicate head lice, but you can have head lice for a long time before the scalp gets itchy.

School board policies

Halton school boards have a “No Nit” policy. Schools outside Halton Region might have different policies. The Halton District and Halton Catholic school boards head lice policy has letters than can be sent to parents to assist with limiting the spread and re-infestation of head lice.


  • Public Health does not provide a service for head lice check-in.
  • Halton schools have contracts with CBI Home Health (formally known as We Care Home Health Service), which deals with management. Contact CBI Home Health at 905-507-6562 and press 3 or 1-855-507-6562 and press 3

Returning to school

Students cannot re-enter the school until:

  • Treatment to the hair is complete and all nits have been removed.
  • Parents obtain a note from CBI home health (formally known as We Care Home Health Services) for school re-entry.

Contact CBI Home Health (formally known as We Care Home Health Services) at 905-507-6562 and press 3 or 1-855-507-6562 and press 3.

Cleaning a classroom after an infestation

For head lice, normal routine cleaning is enough. Never use pesticide sprays, as they are dangerous to your health and are unnecessary.


Re-infestation is when head lice keep coming back. It involves finding new nits ½ inch away or less from the scalp or by finding adult head lice. Re-infestation is almost always due to head-to-head contact with an untreated person.

  • Try to find out why re-infestation is occurring, as it will decrease the need to retreat with head lice products.
  • When re-infestation occurs, have parents check with their pharmacist or doctor to see if they should repeat the head lice treatment.
  • Never use head lice killing products on a daily basis.
  • Re-infestation is not due to resistance to the head lice killing product, but from not following product guidelines and not using the product correctly. Please re-read instructions carefully.

Strategies for parents

  • Teach children to vigorously brush and comb their hair every night. This will injure the head lice and prevent them from breeding.
  • It might help to braid long hair or put it into a ponytail.
  • Check your child’s head once a week, especially around the ears and the neck area.
  • Be especially watchful after group activities, such as sleepovers and camps, where head-to-head contact could have occurred.

Where to get help

If you have concerns about head lice: