It was 10：00 at night. Eight﹣year﹣old Alice opened her eyes. She got out of bed and walked to the kitchen. She opened the fridge, got a sandwich and ate it. Then, she went back to the bed and slept. The next morning, she woke up in bed and found some bread pieces on her sleepcoat. What happened? She had no idea. Later, her mom told her," Dear, don't worry. You sleepwalked last night. "
Sleepwalking is, in fact, very usual in children. Scientists say about 29% of children under 13 have this problem. They get better as they get older. Some adults （成年人） sleepwalk, too. Many sleep﹣walkers can't remember what they did. They often find out later from their families or roommates.
Why do people walk in their sleep? Scientists find people usually sleepwalk in deep （深的） sleep, during the first hours of the night. At that time, the brain （大脑） is sleeping, but the body is not. The sleepwalkers can walk around or do easy things. Some could even drive, study or paint.
But a sleepwalk lasts （持续） only some minutes.
▲Scientists say that we don't need to wake them up, because it is not dangerous. In fact, the best way is to take them back to bed. And remember to do it slowly and quietly. Let them sleep. Tell them what they did the next morning.
