My 8 month old too. He started doing that when he's 7 month n has learned to crawl. We let him sleep on mattress on the floor. There was once he woke up n crawled to the door without us knowing! I came into the room n found him at the door. I read online (I think it's babycenter) that this is because baby wants to practise their new skills even during their sleep. He wasn't a good sleeper. Even when he's 4 month old, he'll wake up to flip over n then cried coz he couldn't flip back over. I suggest dont't play with her. Put her back to sleep, talk softly, carry her to soothe her etc. my baby refused yao lan so we can only carry him until he sleeps or i nurse him back to sleep on the bed. I also find that if he's less over tired n less over stimulated in the evening before bedtime, he'll sleep better.