Head lice -- those wingless parasites that infest between 6 million and 12 million kids each year, according to the Centers for Disease Control and Prevention (CDC) -- need human blood to survive. Specifically, blood from the scalp. They most commonly spread through direct contact between human heads, but they can't live off of that exact location for more than 48 hours.
Know this, and you've got an edge on these nasty bugs.
"Head lice don't jump, hop, or fly," says Sally Kelly, R.N., a school nurse who makes lice-removal house calls in and around Chatham, New Jersey. "They only crawl. Hair has to touch for a louse to travel from one kid to another." This often happens when kids press their heads together to look at video-game screens, or when they hug or play with one another's hair. "It's not about being dirty or clean," explains Kelly. "In fact, in my experience, lice seem to prefer clean hair. It may be because it could be easier for them get around in."
"It's actually harder to get head lice than you'd think," says Kelly. "They don't live on surfaces." She explains that a head louse thrives on the blood type it feeds on at birth, so a louse may transfer to another head but die quickly if the host isn't compatible. Sometimes, a single louse will crawl onto a child's head. If that louse is male, it will just die.
Nits are not transferable. If you comb them from your child's head, they die. For reasons experts don't quite understand, lice don't live on pets.
If you do find lice or nits, meticulously comb out your child's hair with a special nit comb for five days in a row. (Kelly likes the LiceMeister comb, available online.) You can also use an over-the-counter pesticide treatment, but you'll also have to do a comb-out with that method. Kelly recommends doing a final comb-out two weeks after the initial treatment.
"Wash the sheets and comforters once," says Kelly. After that, you can put the comforter in the dryer and roll a sticky lint brush over the sheets for the next five days for extra peace of mind. Wash the child's towel and pillowcase daily for five days, too.
Many parents worry that they'll also have to wash things like bed skirts and bike helmets. Not so, as long as your child's head hasn't been in contact with those places for 48 hours. This is the maximum amount of time lice can go without a "meal."
"When a louse is off of the human head, it's pretty much done," she says. "It needs to feed several times a day, so it would have no food and die."
In general, focus your efforts on those daily comb-outs.
"Don't get too freaked out about the house," says Kelly. "Lice don't live on your pillows or sheets or the rug. They're not like bedbugs. They want to live on a warm head where they can survive, so doing more cleaning than this is only creating more work for yourself."
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