Marianne had a phone call she would never forget. Her daughter's preschool called and asked her to pick up her child because she had lice.

As someone who had never dealt with  growing up and whose older daughter had sailed through childhood without the problem either, she was not too sure she'd find. (Marianne didn't want to use her last name to protect her family's privacy.)

At first glance, 4-year-old Anna looked fine 鈥 save for the occasional itch. It wasn't until one of the school staff parted her hair that Marianne noticed the pesky critters nested in her daughter's hair. For the next few weeks, Marianne tried all kinds of treatments, only for the lice to keep coming back.

鈥淚 couldn't emotionally deal with my disgust at the entire situation,鈥 she said. 鈥淚 wanted to burn my house down.鈥

Any parent dealing with head lice can probably relate to this situation. These parasitic insects burrow deeply into the root of hair and suck the blood from people's scalps. Female lice also attach sticky unhatched eggs called nits to hair. These eggs take  to hatch and can trigger another infestation if not removed, leaving children to have head lice several times a year.

Head lice have unfortunately become a part of raising children today, said Deborah Altschuler, president of the National Pediculosis Association. Knowing how to identify and safely remove them as early as possible can minimize irritation to the scalp.

WHERE DO HEAD LICE COME FROM?

Researchers aren't exactly too sure where lice first originated, just that they have been resilient enough to survive millions of years, feasting on human blood. (The oldest evidence is a  nit found on human hair at an archaeological site in Brazil.)

Head lice are most common among young children 鈥  occur yearly in children between 3 and 11 in the US 鈥 though adults are vulnerable to head lice as well.

Children are most likely to get lice because they are frequently in close contact with each other, said Dr. Danelle Fisher, a pediatrician and chair of pediatrics at Providence St. John's Health Center in California. 鈥淜ids sit (for) hours in school classrooms together and love to share things. They will share toys, food and hats.鈥

It doesn't take long for lice to jump to another head. Marianne recalled Anna coming home and talking about a themed hat day in her first-grade class along with all the different hats she swapped with her friends. 鈥淚 just knew we were in for it, and I was right because she had lice again.鈥

Lice have no preference and don't care about age or gender. It's easier to burrow and conceal themselves in hair, so people with short hair are less prone to a lice infestation.

HOW TO SPOT LICE

If your child is repeatedly complaining of an itchy head, scratching more than usual or having red bumps on their scalp from constant scratching, it's possible they have lice. A  is one way to see if your child has head lice.

With gloves, part different sections of hair and look for poppy seed-sized insects crawling on the scalp or base of the hair shaft. Nits are easier to spot because they will look like white or yellowish-brown specks in the hair near the scalp. If you're unsure whether it's a nit or dandruff, the US  recommends trying to pull it off. It's likely a nit if it's difficult to remove.

A visual exam is good if there are a lot of nits, but some lice may be too small to notice because they move fast and avoid light as much as possible. The best way to check if a child has lice is with a lice comb, Altschuler said. 鈥淪creening with a comb can be four times more efficient in detecting an infestation than a visual exam.鈥

WHAT'S THE BEST WAY TO GET RID OF LICE?

There are many options for treating lice infestations. One is to buy special lice shampoos and conditioners, although these products are not always guaranteed to work.

Unfortunately, lice are smart, Fisher said. They learn to recognize the chemicals in such hair products and try to evade them. 鈥淭hese little insects will become resistant to some of the chemicals we use to get rid of them, which has been incredibly frustrating,鈥 she said.

If you still want to go the shampoo route, Fisher recommends seeing your child's pediatrician to write a script for prescription shampoos containing stronger chemicals than the over-the-counter options.

Experts say the best way to remove lice is the comb-out method. After wetting hair, Fisher advised parting it into small sections and then combing each section several times using a fine-tooth comb.

鈥淵ou're going to want a comb with bristles close together because they are going to be the best for picking up nits,鈥 she said. Each time you run the comb through the hair, wipe the comb with a wet paper towel to remove any lice and nits.

Washing and combing out hair can be a time-consuming process, but they need to be done more than once. 鈥淪ome people think it's one and done, but it's not always like that,鈥 Fisher warned. You may have missed some nits, and if they hatch, you will need to start the process over again. She recommended following up with a second treatment one to two weeks later.

鈥淵ou will never get all those nits out the first time no matter what you do,鈥 Marianne added. She said it took two weeks of combing and shampooing until she no longer saw any lice.

HOME REMEDIES MAY NOT WORK

There are some remedies you can try at home, but Fisher said they might not be the most effective in getting rid of lice infestation. Saturating the hair with mayonnaise or olive oil is popular and can help with suffocating lice.

鈥淚f you want to glob a bunch of mayonnaise on your kid's hair, you still need to follow up that initial treatment with picking through the nits on each strand of hair because those treatments are not 100% foolproof,鈥 she warned.

Another option parents may turn to is cutting their kid's hair. Fisher does not necessarily recommend such an extreme option, though she has seen some families use this method to help eliminate lice. It only works if you go completely bald, and it may not be the most appealing route if you have luscious locks. Plus, Fisher said this approach will not work if you cut your hair super short because lice only need a small fraction of hair to live on and lay eggs.

If you are unsure whether you got rid of all the nits, professionals at lice clinics can come in and do a thorough comb-over for you.

To prevent these parasites from coming back, Fisher advised everyone in the household be checked for lice as a precautionary measure. You'll also want to wash all the blankets, towels and pillow covers with hot water.

Jocelyn Solis-Moreira is a New York-based freelance health and science journalist.