If you find lice to be going around at school, a good way to safeguard your child, or to try to, is to spray his or her hair with hairspray. You can also use hair gel or any other kind of hair product. The lice are repelled by the chemicals, and they rather like clean hair that can be penetrated. So don't react by overwashing!
ALSO: If your kids or you ever actually get lice, use "NIX" brand of lice removing hair conditioner, as it's the only lice treatment that KILLS THE EGGS (nits) too. This way, you usually have to only use it once, not again & again, like the other brands, because it kills the flea-eggs or nits. Men, Don't forget your beard & facial hair.
If I still had small kids, I don't think I'd use NIX "every 30 days" because it's full of nasty chemicals & who wants nasty chemicals on their kids scalp!
---> BEWARE: I once got lice at the thrift store from trying on hats! If you really want to try on a hat, first look in VERY carefully for any nits or lice... You may not even be able to see the tiny little buggers, so use care when trying on clothes that used to belong to others, or clothes & hats that others may have tried on only minutes before you! Don't be paranoid, but just think first.
If you do get lice, you can kill them easily with any oil. Just soak your head with baby oil, vegetable, even mayo, cover with a shower cap for a couple of hours and your good. They suffocate!
When my kids were little, and we had a problem with re-occuring infestations, because of "Friends" that would not treat their children, I was told by a nurse, frequent treatments are very dangerous to your child. Because the lice treatment is a pesticide. Keep that in mind with the re-treatments over and over. Also, I learned, that putting the girls hair up, then spraying it with a hairspray or hair gel that has alcohol in it, keeps the little critters away.
My sons have brought home lice more than once over the years. The most effective deterrent that I have found is tea tree shampoo and conditioner. There are many brands available but the one I regularly get is from Trader Joe's. I have also taken straight oil and added it to regular shampoo.
Another thing I have done with my boys is to use a flat iron. They both are teenagers now and have long hair. The heat of the flat iron will kill both the lice and the nits.