What Do Head Lice Look Like?

At some point, you might receive a dreaded note from your kid's school about exposure to head lice. It shouldn't come as much surprise, since the Centers for Disease Control and Prevention (CDC) estimates that anywhere between six million and 12 million kids are infected yearly in the U.S. But when you get that note, what exactly are you looking for? What do lice look like?

Head lice develop in three stages, from egg to nymph to adult, and a louse looks different at each stage. Lice are light-colored and commonly mistaken as dandruff. They like to live near the scalp and along the hairline, where they can easily obtain a blood meal. So, when checking for lice, you'll want to use a comb to part the hair and see the areas near the scalp and along the forehead, ears, and neck.

Here's all you need to know about what head lice and nits look like.

What Do Nits Look Like?

Lice eggs are known as nits. They're oval-shaped and tiny—similar in size to a knot in thread. Nits are difficult to see, but you can feel them if you run a fingernail down the hair shaft from the scalp.

Nits are usually light gray, tan, yellowish, or white. "They can look just like a grain of sand, and they're not easily removed from the hair," says Paradi Mirmirani, MD, a board-certified dermatologist with the American Academy of Dermatology.

Nits usually take a little over a week to hatch. After the nits hatch, their dull yellow shells remain on the hair shaft. Adults lay about six eggs per day, says the CDC, so it's easy to see how an infestation can get out of hand as lice multiply quickly.

What Do Nymphs Look Like?

An immature louse (or nymph) looks like an adult, but it's about the size of a pinhead, according to the American Academy of Pediatrics (AAP). To stay alive, nymphs must feed on human blood. After about nine to 12 days, nymphs become mature adults.

What Do Adult Lice Look Like?

Adult lice grow to the size of a sesame seed. You'll notice six clawed legs and a tan or gray color. The CDC says lice may look darker on people with dark hair.

Like a nymph, an adult louse survives on regular human blood meals. Adults can live about a month on a human head, but once they fall off, they die quickly—generally within a couple of days.

Other Symptoms of Head Lice

Now that you know what head lice look like, you may be able to identify them on sight. However, sometimes seeing a bug isn't the first sign of lice. According to the American Academy of Dermatology Association (AADA), other symptoms of head lice might also include:

• Itchy scalp
• Excessive scratching, which might lead to irritation or sores
• Feeling a crawling sensation

In addition, if you scratch excessively, you may be at risk of a bacterial infection from breaking the skin. If that happens, you may experience swollen lymph nodes or pink eye.

According to the AAP, some things that might be mistaken for head lice include dandruff, dirt, and hair product particles.

Where Can You Find Lice?

Head lice and their nits are found almost exclusively on the scalp, particularly behind the ears, on top of the head, and near the neckline. They sometimes appear on eyelashes and brows, but this is rare.

Lice grasp the hair shaft with hooklike claws. Since they don't like light and are extremely fast, you may only see or feel the nits when closely examining your child's hair.

Grab a flashlight, and look or feel for the tiny bumps, which will be cemented firmly to the hair shaft about a quarter-inch from the scalp. Lice can be tough to remove even after hatching when only the empty casings remain.

Do your best to remain calm if you find nits or head lice when examining your kid's hair. A lice infestation is an annoying problem but a solvable one. "Remember: Lice don't carry disease," says Dr. Mirmirani. "They're icky, yes. But they're no harm to your child's health."

How to Treat Head Lice

Over-the-counter (OTC) and prescription medications called pediculicide kill lice and nits. To treat head lice, the CDC recommends the following steps:

1. Remove clothing that you don't want to be stained.
2. Use the medicine according to the package directions.
3. Comb out dead and remaining lice with a fine-tooth nit comb.
4. Continue combing with a nit comb every couple of days.
5. Re-check hair for several weeks to ensure lice are gone.

In addition to treating the infected person, you can take additional steps to kill lice that may have fallen off. For example, wash bedding and clothing in hot water and dry them on high heat. You can keep items that can't be washed in sealed plastic bags for two weeks, during which time any live lice on the items should die.

In addition, soak combs and brushes in hot water for 10 minutes, and vacuum your floors and furniture as an extra precaution (though it's true that lice can't live for very long off a human host).