Why do people talk in their sleep?

Have you ever been told that you talk in your sleep, or shared a room with a friend or sibling who does? While we often think of a sleeping person uttering nothing more than the usual "zzzz's," talking while asleep is actually pretty common!

In fact, about 5% of grown-ups are said to sleep-talk, and about half of all kids! The medical name for talking in your sleep is "somniloquy" and nobody knows exactly why it happens but most experts agree that it's not usually something you need to worry about. There are some things that have been found to trigger sleep talking, such as having a fever or keeping an irregular bedtime.

It can also be the side-effect of medicine or the result of stress. The things said by sleep-talkers often sound like nonsense or are hard to understand. Even when a sleep-talker is saying something you can understand or having an entire discussion, it's usually something with little or no real meaning. Weird!