A louse is a parasite (say: PAR-uh-site), which means it feeds off of other living things. Lice (the word for more than one louse) are about the size of a sesame seed, and are tan to gray in color. Lice need to suck a tiny bit of blood to survive, and they sometimes live on people's heads and lay eggs in the hair, on the back of the neck, or behind the ears.
It's very easy for a person with lice to give it to someone else when they come into close head-to-head contact with each other. Sometimes, lice can be transmitted by friends sharing things that have touched the hair, such as combs, brushes, hats, and headphones. Lice cannot jump or fly, so a person can't catch lice by simply sitting near someone who has lice.
What a Bite Looks and Feels Like
If a person gets lice, it doesn't feel like anything at first. A louse lays tiny, oval eggs called nits. They are yellow, tan, or brown before the lice hatch. After the lice hatch, nits appear clear or white. They look a little like dandruff flakes but they can't be shaken off.
The lice mature within 1 to 2 weeks and begin feeding on the scalp and attaching their tiny claws to a person's hair. Louse bites are very itchy, and can get red when scratched. A lot of scratching can lead to open sores and infected skin.
What You Should Do
If your head is very itchy, tell an adult immediately. Getting lice has nothing to do with being dirty, and it's very common among kids who are in school together. It is something that will need to be cleared up as soon as possible.
What a Doctor Will Do
Doctors treat people who have lice by giving them a prescription for a medicated shampoo, cream, or lotion that kills lice, or instructing that they buy one of these at a store.
An adult will need to use a fine-toothed comb to get rid of the existing nits and follow the instructions for putting the medication in your hair to kill the lice. It's not a good a idea to use a hairdryer to dry a person's hair after using the medication, as some medicines contain flammable ingredients (which means they can catch on fire and burn easily).
It may take a few days for the itching to stop, and the treatment may need to be repeated in 7 to 10 days to make sure any surviving lice are killed before they produce new eggs.
Sometimes, adults choose to skip the medicated shampoo and only use a fine-toothed comb to remove the lice and nits from the hair. They'll need to do this many times (every few days) to make sure to get everything out. But as long as the adult and the kid both have the patience to do this (maybe read a good book while it's being done), it works just as well.
Because they need to feed a few times a day, lice can't live more than a day or two off of a person's head. To be on the safe side, your parents may:
vacuum carpets and furniture
wash bedding, clothing, and stuffed animals that could have come in contact with lice (these also can be put in airtight bags for at least 10 days to kill the lice and eggs)
soak brushes, combs, and hair accessories in hot water, or throw them away
But the most important thing is to check the heads of everyone who lives in the house for lice.
How to Avoid Getting Bitten
It can be hard to avoid lice completely, but there are things you can do to protect yourself:
If you know kids with lice, avoid putting your heads together.
Always bring your own pillows, sleeping bags, or sheets to a sleepover.
Do not share brushes, combs, hats, headphones, or hair accessories (like barrettes and headbands) with anyone else.