Head lice are tiny insects that live and breed on your head. They can live for up to 30 days on a person’s head and need to feed on blood to survive.

Head lice are tiny, wingless, move quickly, and are hard to see. They crawl as they cannot jump or fly. They are about the size of a sesame seed and greyish brown in colour.

Nits are head lice eggs and are about the size of a grain of sand. They are hard to see and are often confused with dandruff. They are oval in shape and usually yellow to white in colour. Nits are glued to the hair and hard to remove. They take about 1 week to hatch.

Anyone who comes in close head-to-head contact with someone who already has head lice can get head lice.  Head lice are more common in children between the ages of 3 – 10 as their heads often touch when they play together.

By close head-to-head contact with someone who already has head lice. Contact is common during play at school and at home. Head lice are also spread by using hats, scarves, combs, brushes, hair ribbons, pillows or towels recently used by someone with head lice.


  • Tickling feeling of something moving in the hair.
  • Itching, caused by an allergic reaction to the bites.
  • Irritability.
  • Sores on the head caused by scratching. These sores can sometimes become infected.

Check all close contacts, if one person in the household has head lice there is a good chance that other people at home do too. It is important to check the head of every person in the home but only treat those who have head lice. Treat everyone with head lice in the household at the same time.

  • children under two years;
  • a person with a seizure disorder;
  • a person with a scalp infection;
  • OR if you are pregnant or breastfeeding.

A pharmacist can help you choose a head lice product that is right for you. The products suggested by the pharmacist are proven effective if they are used as directed.

One treatment may not kill all of the nits. Applying a second treatment 7-10 days after the first treatment to kill any newly hatched lice is recommended.

  • Use a bright light to help you see the lice and nits.
  • Carefully check all parts of the head for live lice and nits every day between treatments.
  • Remove any nits you see by using your fingernails or a nit comb.
  • Drag each nit starting from the roots of the hair down to the tips.
  • If you see live lice 48 hours after the first treatment, talk to a pharmacist for further instructions.
  • Toronto Public Health recommends the removal of all nits as head lice products are not 100% effective.
  • Wash hats, scarves, hairbrushes, combs, or any other item that is worn or used on the head.
  • Wash pillowcases, towels and bed linens after the first and second treatment in very hot soapy water.
  • For items that cannot be machine-washed, dry clean or place in an airtight bag for 10 days to two weeks.
  • Vacuum surfaces where heads have rested (e.g. sofas, seats of cars and helmets).
  • Excessive house cleaning is not necessary.
  • NEVER use insecticide sprays.
  • Teach your child(ren) how head lice are spread.
  • Discourage head-to-head contact and sharing of hats, scarves, hairbrushes and combs.
  • Tie long hair back in braids.
  • Check the head of young school age children weekly for head lice; more often if there is an outbreak.
  • Routinely check the heads of all people living in the household for head lice.
  • Treat all people with head lice in the household at the same time.
  • If someone in your household has head lice, tell all people who have close contact with the person with head lice to check their heads, including the child’s teacher and/or daycare worker.
  • Be sensitive to people’s feelings. People with head lice should not be made fun of or made to feel embarrassed.
  • Lack of cleanliness does not cause head lice.
  • Both children and adults can get head lice.
  • Short hair does not prevent the spread of lice.
  • Head lice do not live on dogs, cats, or other animals.
  • You cannot prevent head lice by using head lice shampoos or products – use them only if you have head lice.

Download a copy of the Head Lice Fact Sheet (also available in French). To obtain a copy of the Head Lice Fact Sheet in other languages, please e-mail publichealth@toronto.ca or call Toronto Health Connection at 416-338-7600.