Scariness comes from fear of the unknown, from surprise, and from fears about the loss of a loved one. Different things scare different children; it's not always possible to predict what will frighten a particular kid. Young kids are frightened more by creatures that older children know don't exist. Abrupt noises, eerie sounds, and music create tension in both younger and older children. Psychological suspense, with its threats of impending doom, can terrify your middle-school kids.