We've all been there: The dreaded lie alert letter that comes home in your child's backpack. Reading it, we begin to scratch our heads, while making a mad dash for a fine tooth comb, magnifying glass and flashlight to examine our kid's braids, buzz cut, ponytail—you name it. Relax, here's what you need to know:

What exactly is head lice?

Are they killer, disease-hungry bugs poisoning our kids? No way. First off, one single critter is called a louse. They're teeny insects that are about the size of a grain of rice. They are pale and gray. It's even been suggested that kids don’t skip school if they have an infestation. (Although as a parent, I beg you! Keep your kiddo home.)

Who gets it?

Anyone. However, it's most common in children in daycares and elementary schools because they tend to jump allover each other during play. Be warned: Lice actually like clean hair, so be careful pointing fingers at the "smelly kid" or the rocker with pink locks and heavy product in their hair.

“My middle-schooler is of the age where she showers and washes her hair every morning, blowing it out, too. She has long hair, parts it in the middle and is off," says Pat O., from Ohio, Calif. "She was horrified she had lice—'My hair is so clean,' she yelled over tears."

What do they want?

Call them little vampires; lice want blood. They feed on tiny amounts of blood from the scalp. But after they suck your kid's blood (it's not painful, mostly itchy), the good news is they survive less than a day.

How long do they haunt us?

They live about 28 days and multiply very quickly, laying around 10 eggs a day. Twelve days later, the eggs have hatched and are crawling around in your kid's head. The cycle can, and will, repeat itself every 3 weeks if head lice are left untreated.

"I remember the year our daycare was shut down by the Board of Health because the staff couldn't get rid of the lice. Parents thought they were doing right by their kids, but if you miss one nit, it's all over," recalls Kathy G. from Washington.

Lather up

"Use a shampoo or lotion specially formulated to attack and kill the problem. This usually involves lathering the shampoo into the hair and leaving it on for a few minutes before rinsing it out," says Dr. Paradi Mirmirani, board-certified dermatologist and member of the American Academy of Dermatology.

Rinse hair and comb

Dr. Mirmirani suggests gliding special comb (found at most drugstores) through your kid's wet hair. The teeth on the combs are much closer together than regular combs and are more likely to remove the lice and nits.

Continue to check!

"This is often easier to do with wet hair. Lice don't live very long off the human head, so your best bet is to spend most of your energy combing through the hair daily," she says.

Control infestation between students and family members

"They don't fly or jump, but they often spread when kids put their heads together," Dr. Mirmirani says.

So in other words, no wrestling or hugging during the treatment process.

"When my toddler came home with lice from daycare, I didn't allow him near his first-grade sister. I literally quarantined him in the pack and play and took him to the pediatrician to give us the all-clear before returning him to school," says JoJo B., from Virginia, who missed four days of work dealing with lice.

Clean!

"Use hot water to wash clothes, sheets, pillowcases, blankets and anything the person's head may have touched. Seal non-washable items, such as stuffed animals, in a plastic bag for several weeks," advises Dr. Mirmirani. (Or toss things that aren't sentimental!)

She says also suggests vacuuming the carpets and furniture.

"Do not use 'killing sprays!'" she warns. "Harsh chemicals can cause more harm than the lice."

Prevent

While the jury is still out on whether or not we can prevent an outbreak, we do know certain smells turn them off.

They suggest using products, such as shampoos and conditioners made with rosemary and mint, nightly. Products like repel spray and gel with the same scents are great for back-to-school season. 

"My son came home with lice. I freaked out but was able to treat him with over-the-counter shampoo and keep him clean," she says.

How? Jenn jumped online and learned that lice hate the smell of strong herbs, such as tea tree oil, peppermint, lavender, rosemary and eucalyptus oil. They also hate the texture of oil, so essential oils play double duty.

"I run a small amount of oil through his hair daily," Jenn says. Bonus: "It smells great."