Head lice are tiny insects that bite into the scalp and feed on our blood. They are almost always found in the hair of our scalp but can sometimes even be found in our eyebrows and eyelashes1.
What do head lice look like and how long do they live for?
Not every louse on the scalp looks the same. There are usually lice eggs (also called nits), nymphs (young lice) and fully grown adult lice.
Life Cycle of Head Lice2
Nits are head lice eggs. They are very small (the size of a single knot in thread) and usually have a whitish-yellow colour. The eggs are laid by an adult female head louse on the shaft of a single strand of hair, right up against the scalp. They are often mistaken for dandruff and take about 8-10 days to hatch into a nymph.
Nymphs are young head lice that have hatched from the egg, and looks like a smaller version of the adult louse. They feed on blood from the scalp for about 10 days before they mature to become an adult.
Adult lice are about the size of a sesame seed. They also feed on blood from the scalp and have a lifespan of about 30 days. The female can lay up to 6 eggs per day3.
Did you know: Lice need to eat blood from our scalp to survive. If they fall off the scalp, they will normally die within 1 to 2 days.
Where do they come from?
Head lice have been around for as long as humans have been alive. They are found in every culture and are found in all parts of the world4.