For early grade-schoolers, everything from "Aliens are under the bed" to "Will a watermelon grow inside me if I swallow one of the seeds?" are real concerns. Kids this age understand more than they did when they were preschoolers: They know there are bad guys out there and that people can get hurt and die. They're also seeing movies or listening to books that can be a little more grown-up. Even if they don't seem to react badly at first, those complex fictional situations can make them uneasy at night or during stressful times -- the birth of a new sib, a move, starting school.
But your kid's worries shouldn't cause you sleepless nights. All kids have fears; it's a basic human emotion, say experts. Most of the time, your child can work through his anxieties with your help -- by talking about his fears, for instance, or learning such self-comforting techniques as taking deep breaths. But if your child refuses to go to school or avoids other social situations, often complains of stomachaches, or has trouble sleeping, talk to your doctor.