1. Diagnosis Can Be Tricky
The best way to confirm an infestation is to find a live louse. Use a magnifying glass and a fine-toothed comb to search. Nits more than a quarter-inch from the scalp are almost always dead, and usually the infestation no longer needs treatment. If you’re unsure, ask a doctor or health department official.

2. Lice Love Humans
Head lice have claws specially designed to cling to human hair. To survive, they huddle close to your scalp, eating blood several times a day. A single bug, called a louse, can live up to 30 days on your head but dies within a day or two if it falls off.

3. Children and Adults Can Get Them
Head lice infest younger children in child care or school first because they play closely together. An estimated 6 million to 12 million cases occur each year among kids ages 3 to 11. But adults can get head lice, too. If one child in your house is infested, it’s best to check everyone.

4. They’re Sometimes Mistaken for Dandruff
Nits are head lice eggs, and they’re small, oval-shaped, and tough to spot. People who detect them often think they’re dandruff, scabs, or droplets of hairspray. If they’re not treated, they’ll hatch into nymphs, or young lice, within eight to nine days. Within about another seven days, they’ll become adult lice.

5. Skip the Home Remedies
There’s no proof mayonnaise, olive oil, margarine, or butter kills lice. However, nondrug methods can supplement pesticide treatment. Wash clothing, linens, combs, and brushes with hot water. Vacuum floors and furniture. But don’t spend too much time or money; lice can’t live long if they’re not on a human host.

6. Over-the-Counter Products May Solve the Problem
Some medicated shampoos and creams are available without a prescription. Called pediculicides, many contain the ingredients pyrethrin (such as the brand Rid) or permethrin (Nix). Read the instructions carefully. Ask your doctor before using them if you’re pregnant or if you or your child has allergies or asthma.

7. Your Doctor Can Also Prescribe Treatments
Prescription-strength creams, lotions, and shampoos kill lice when milder products can’t. Some may be safer for pregnant or breast-feeding women. These treatments may contain the ingredients ivermectin (Sklice) or benzyl alcohol (Ulesfia). Some may require the use of a fine-toothed nit comb after each application to remove remaining nits.

8. They’re Sometimes Mistaken for Dandruff
Nits are head lice eggs, and they’re small, oval-shaped, and tough to spot. People who detect them often think they’re dandruff, scabs, or droplets of hairspray. If they’re not treated, they’ll hatch into nymphs, or young lice, within eight to nine days. Within about another seven days, they’ll become adult lice.

9.  They’re Not a Sign of Poor Hygiene
Head lice spread through direct head-to-head contact. For kids, this often occurs at school, sports activities, camp, or slumber parties. Less commonly, lice travel on hats, scarves, coats, brushes, or combs. The cleanliness of your hair, home, or school has nothing to do with the risk of getting them.

10. Check Your School’s Policy
Most elementary and grade schools have rules regarding head lice infestations. For instance, some don’t allow infected children at school until they’re free of nits. To prevent the spread of lice, tell children to avoid contact with the hair of infected friends or classmates.