Fact Sheet

What are Head Lice?

Head lice are insects that live and feed on the human scalp and lay their eggs by attaching them firmly to the hair. The adult louse is about the size of a sesame seed and is brown to reddish brown. They can move quickly but cannot hop or fly. They are difficult to see because they move quickly away from light. An adult female may lay between 50-90 eggs. The eggs also known as nits, hatch in 7 days and grow to adulthood in about 2 weeks. Nits are about the size of (-) are oval in shape and are tan, brown, or white.

Nits and Adult Lice

Louse at different stages of development 
(Lice is plural for louse)


<———- Adult louse 
<———- Baby louse (nymph) 
<———- Nit (egg) on a hair strand

How is Head Lice Spread?

Head lice crawl and most of the time are spread by head to head contact, such as when kids are playing together, or sleeping over in another house. It is possible but less likely that they are spread by using pillows, combs, hats or clothes etc. recently used by someone with head lice.

When should I check for Head Lice?

Check hair if child is complaining of itchy head/scalp or if you see anything resembling dandruff, take a closer look. After one has had head lice for a few weeks, the head will become very itchy in most cases but not all. Head checks should be done at home as weekly routine for pre-school and school-age children.

How do I check for Head Lice?

Under bright lighting check the hair close to the scalp for either the insects or their nits. Check especially the area at the front of the head, around the ears and the nape of the neck. You may not actually see the insects, as they hide from light and from being disturbed, but the nits or eggs do not move. Nits can be distinguished from dandruff in that they are firmly attached to the shaft of hair and cannot be removed by blowing or flicking with a fingernail.

If you check for head lice often at home and they are found on your child, you can begin treatment early and save time, effort and money in getting rid of them.