Camp, slumber parties…head lice. When kids come in close proximity to one another, lice tend to leap from one BFF to the next.“A lot of people assume that when school starts everyone comes down with lice. But many kids get exposed to it during the summer and just don’t know it,” said Mandy Ottesen, owner of Fresh Heads Lice Removal in Jacksonville, Fla.First the creepy facts: Lice are parasitic insects that take up residence on our scalp and feast on human blood several times a day. The unhatched eggs they lay are called nits. Nits are about the size of a knot in a piece of thread, while adult lice are roughly the size of a sesame seed. While they are not known to spread disease, there’s no denying they’re a nuisance.MORE: 12 Snacks For Super HairPreventative Shampoos: Do They Work?These better-safe-than-sorry sudsers use strong, essential oils such as rosemary, eucalyptus, peppermint, lemon grass or tea tree oil to repel lice. The idea is that when used daily, they make your head smell “very perfumey and not like a person,” explains Jessica Sammis,Owner of Nit Nabbers in Charlotte, NC,“None of these preventative shampoos have any effect on lice eggs though,” adds Ottesen. And to make matters worse, roughly 30 percent of the time, they won’t do anything to live bugs either. So while they may have some olfactory effect, they also give a false sense of security.MORE: The Science Of HairTreatment ShampoosSo your child has lice. The first step is to avoid freaking out. “You don’t have to tear your whole house apart,” explains Sammis. In addition to cleaning sheets in hot water and a hot dryer along with a good vacuuming, certain shampoos will help strip kids’ strands of these pesky creatures.One such brand, Fairy Tales Hair Care, markets a line of prevention and treatment shampoos and conditioners that are “loaded with organic herbs to cleanse, condition, style and most importantly, help repel hair lice.”Another company, Jolis Cheveaux, also sells an all-natural, non-toxic shampoo they say is safe for children and used by professional technicians to treat and prevent lice infestation at home, school or camps.What makes them work?“These cleansers either use an enzyme that breaks down the glue that the lice use to hold onto your head (so when you comb, they come out easier),” explained Sammis. “Or the formula incorporates a very oily liquid, like olive oil or coconut oil, which smothers live bugs and suffocates them.” Active ingredients can also include pyrethrins—a naturally occurring insecticide from the chrysanthemum flower, or permethrin lotion—a synthetic pyrethroid.If over-the-counter shampoos don’t work, you can get a stronger prescription shampoo that contains either malathion lotion, an organophosphate chemical often used as the base for insecticides, or benzyl alcohol lotion, an aromatic alcohol. Both substances are FDA-approved, but kids under 6-years-old should steer clear of malathion.Take note though, these shampoos only kill live lice, not unhatched eggs or nits (that’s why most recommend reapplying in 7-10 days). Also, lice can get resistant to these pesticides, warns Sammis.Your best line of treatment? Get a good lice treatment comb and meticulously comb and comb and comb every day until they are gone. These tools have several, densely packed metal prongs that detach lice from stands.Preventing lice in the first place can be difficult and has nothing to do with one’s cleanliness. ”It’s sort of the wrong place at the wrong time,” added Sommis. If your child has a friend with lice, a preventative shampoo is your best bet—along with daily head checks.MORE: Hair Care Tips