Sleepwalking is a disorder that causes people to get up and walk while they're asleep.
It usually happens when a person is going from the deep stage of sleep to a lighter stage or into the awake state. The sleepwalker can't respond during the event and usually doesn't remember it. In some cases, he may talk and not make sense.
Sleepwalking mostly happens in childhood, typically between the ages of 4 and 8. But adults can do it, too.