Babies seem unfazed by darkness; if their mommy is holding them, it doesn't matter much whether it's night or day. By the time the toddler years arrive, though, nighttime can start to seem spooky, and the dark can be seriously creepy to a 4-year-old, thanks to a surge in cognitive development and imagination around that age, says Jonathan Kushnir, Ph.D., a sleep researcher at Tel Aviv University in Israel. While fear of darkness is quite common and totally outgrow-able, it's smart to nip night fright in the bud to avoid prolonged anxiety and interrupted sleep. In fact, infants who rely on their parents for help settling down for night-night are more likely to have night wakings both now and when they're older, too.
One way to help spook-proof the dark is to have your kiddo help pick out a fun nightlight and comfort item. Kushnir's research, featured in the European Journal of Pediatrics, found that sleeping with a new stuffed puppy (the comfort item provided in the experiment) significantly reduced bedtime fears and improved sleep for three quarters of the kids after just one month.
If you want to put this research to the test, give your child a new stuffed toy and tell her she needs to protect her pup (or bunny, duck, whatever). Or tell her the doggy is there to keep them both safe. Experts say either strategy works, so take your pick!