It is not known for sure why children walk and talk in their sleep. Sleep walking and sleep talking are not, however, considered to be serious disorders. Both occur during deep sleep, usually one to three hours after falling asleep. Parasomnias tend to run in families, and children may experience one, two, or all three types.
Sleep talking is more common than sleep walking, but the two often occur together.
The main concern for parents with sleep-walking children should be safety. Sleep walkers do not have the judgment that people who are awake have, and they run the risk of getting hurt. It may be difficult for parents to protect their sleep-walking children. Often, sleep walkers don't make much noise, so it's difficult for parents to tell when their children are sleep walking. However, sleep walkers are in danger of getting seriously hurt.