1. Keep your child away from sick kids. Ear infections aren't contagious, but the colds that can cause them are.
2. If possible, choose a smaller day-care setting. The more children you have together, the more germs they can pass to each other. And the fewer kids, the fewer germs are swapped. How small is small enough? "Scandinavian studies show that five seems to be some kind of cutoff," says S. Michael Marcy, M.D. Smaller day-care centers may also have fewer kids who are on antibiotics, which could cut down the risk of your child's picking up antibiotic-resistant bacteria.
3. Don't expose your child to secondhand smoke. Tobacco smoke can irritate the eustachian tube, causing it to swell.
4. Breast-feed your baby. In one study, infants who were fed formula for the first 6 months of life were 70 percent more likely to develop ear infections than babies who were breast-fed. Breast milk contains protective antibodies that help fight disease. If you do bottle-feed your baby, make sure you feed her in a semiupright position.