What Are Lice? How Do You Know If You Have Them?

The thought of lice might give you the creepy crawlies -- and with good reason. When these tiny mites infect the scalp and skin, they trigger intense itching.

There are different types of lice. The type you have depends on the part of your body that’s affected:

  • Head lice affect the scalp.
  • Pubic lice (also called “crabs”) affect your genital area.
  • Body lice affect other areas of the body and are often found in seams of clothing.

This article will focus on head lice, a very common condition among kids in elementary and middle school. About 6 million to 12 million of them get it every year. Head lice are most active at night. They can cause such intense itching that your child could lose sleep over it.

It’s uncomfortable, but lice won’t make you sick. They don’t spread disease and they’re not a sign that you’re dirty. You can get lice even if you shower regularly and have super-clean hair. These pesky creatures don’t fly or jump -- they crawl over to the closest head they can find. This is called head-to-head contact, and most people get lice this way. But they also can spread onto hats, helmets, combs, bedding, pillows – even ear buds. Young children may get or spread lice when crawling on rugs.

It’s important to know the early signs of lice. Then you can take steps to keep your child comfortable and keep the mites from spreading throughout your home.

Identifying Lice

These pests are a type of insect called a parasite. They need human blood to live. Head lice usually stay close to the scalp and behind the ears. You might also spot them on the eyebrows and eyelashes.

Female adult lice lay six to eight eggs a day on your scalp, and they spread from there. There are three forms of lice to watch for:

  • Nits, or lice eggs. They’re very tiny -- about the size of a pinhead. They’re hard to see. The oval-shaped eggs often look yellow or white but may be the same color as your hair. They stick like glue to the end of each hair closest to the scalp and are hard to remove. You may confuse them with dandruff or flakes from hair spray build-up. Head lice nits usually hatch in 8 to 9 days. When they do, they leave behind clear shells, which remain stuck to the hair shaft.
  • A nymph is a baby louse (singular for lice). It’s what hatches from the nit. It feeds on the blood on your scalp and keeps growing for 9 to 12 days. Nymphs (and adult lice) move quickly and avoid light. Mites begin to appear in your hair, on your skin, and on anything your head has touched. Itching might not start right away.
  • Adult lice are about 2 to 3 millimeters long, about the size of a sesame seed. They’re tan or grayish-white. The color can be lighter or darker, depending on the shade of your hair. Adult lice have six legs with claws at the end that allow them to latch tightly to your hair. Typically, adult head lice live 30 days when stuck to your head. If they fall off, they die within 1 to 2 days.

If you spot lice, tell your child’s school so they can properly clean classroom items and stop the spread. The CDC says lice aren’t a medical hazard, and most health departments don’t require that you report it. But local school boards make their own school lice policies. Check with your child’s school to find out its policy.

WebMD Medical Reference Reviewed by Stephanie S. Gardner, MD on March 08, 2017

Sources

SOURCES:

American Academy of Dermatology: “Head Lice: Overview,” “Head Lice: Tips for Managing.”

CDC: “Frequently Asked Questions,” “Body Lice,” “Parasites-Lice-Head Lice,” Parasites-Lice-Head Lice: Biology.”

KidsHealth: “Head Lice.”

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