You can take steps to avoid lice in the first place by not sharing clothes or grooming items with others. Wash clothes, towels, and sheets often, and bathe every day. Use a flashlight to check children's hair and scalp once a week for head lice before they spread to other family members. August through November are prime months to keep close watch.

• If you already have head lice or your child does, buy an antilouse shampoo at the drugstore. Make sure to treat everyone in the household who has lice at the same time. After shampooing, comb everyone's hair carefully, looking for nits. Though the treatments are good, they don't kill the eggs. Just a couple of overlooked eggs can start a new outbreak.

• Use one bottle of treatment per person. Those with long hair may need two bottles. Have someone else apply and lather the shampoo for you, or do the same for your child. Bend the person's head over a sink (instead of using the bathtub or shower) so that the shampoo stays away from the rest of the body. Work the shampoo into the hair and scalp, without adding water. Make sure to work up a good lather, and don't forget to soap up the nape of the neck and the ears.

Let the shampoo sit for the time advised on the label, usually about ten minutes.

Rinse the hair. Use a fine-tooth comb to remove the lice and nits. Gently scrape the scalp to remove lice from the skin. Rinse the comb often. Comb the hair for as long as it takes to remove all lice and nits. Inspect the hair shafts close to the base to see if any nits are still attached. Rinse the hair again, comb for a few more minutes, then rinse again. Use a separate comb for each person.

You may want to use an extra-fine-tooth comb, such as a metal comb for cats or a flea comb, sold in pet stores. Or try the new LiceMeister comb from the National Pediculosis Association (see Latest Developments). Your fingernails are good tools, too, for nits close to the scalp. After you finish, be sure to wash your hands well, including under your fingernails, to avoid moving any nits to another person or to your own hair.

• Try an over-the-counter lice egg remover after the shampoo treatment. Comb through the hair again with a fine-tooth comb.

• Vacuum carpets, floors, and furniture well. Wash sheets, towels, and clothes in hot water. Dry for at least 20 minutes in a dryer set on high. Iron or dry-clean clothes that can't be washed; the heat or chemicals will kill lice and nits. Seal stuffed animals and pillows that may have lice in plastic bags, and keep them away from children for at least three days.

You don't need to spray permethrin or other insecticides around your house. Lice can't live for long on objects.

• Boil combs, curlers, and brushes in soapy water.

• Don't borrow combs, brushes, hats, sleeping bags, or other personal items from others.

• If your child has repeat infestations of head lice, or if you want to avoid medicated shampoos that contain insecticide, some doctors advise this home aid: Mix 50 drops of tea tree oil (sold in health food stores) in 1/4 cup of warm olive oil. Apply to the hair and scalp and work in. Cover with a shower cap and a hot, moist towel for two hours. Then rinse the hair well and comb out the eggs with a fine-tooth comb.

• Bathe well with soap and water. You don't need to use an over-the-counter antilouse lotion, since these lice don't live on your body.

• Don't try drastic home remedies such as scrubbing your skin with harsh soaps or kerosene.

• Change into clean clothes and use clean bedding and towels.

• Vacuum carpets, floors, and furniture and wash clothes as directed for head lice.

• Lather pubic hair with antilouse shampoo, using the same steps as for head lice. Use it on your armpits as well if you have lice there.

• Vacuum carpets, floors, and furniture, and wash clothes as directed for head lice.

• Make sure your sex partner is treated.