How frequent are nightmares for toddlers, and what causes them? Those are questions researchers at the University of Montreal hoped to answer. They asked parents of about a thousand children to estimate the occurrence of their child's nightmares from age two and a half through age six. The parents were also questioned about their child's disposition. First, it turns out that nightmares aren't so frequent. About a third of the parents reported no nightmares at all. And then there's the second result. Kids who were called "difficult" as early as 5 months were more likely to suffer from nightmares as toddlers. And the ones who at a year and a half were more anxious, more likely to cry, and more difficult to calm down were also more likely to have bad dreams. The study authors say this means children may be, well, like little adults. It’s already well established that adults tend to express real-live stress and emotional problems as nightmares. The researchers suggest that focusing on the kids' day-time issues, and on parenting techniques, may help banish night-time demons.