Bad Dreams Perhaps?

Can 9 month olds have bad dreams? Last night something odd happened. He awoke around midnight whailing in his crib. I got up... thinking perhaps he was cold or had his leg stuck in the crib bars or something... and I found him standing up holding the side of the crib. He didn't want milk, a blanket or a pacifier. He didn't have a fever. His leg wasn't wedged between the bars. He was tired and upset for seemingly no reason.

I picked him up and sat with him in the glider singing to him to calm him down. That seemed to work for the most part, but then he got squirmy again. Maybe gas? He had been sleeping for 4 hours... it's unusual for him to just wake up like that. He typically sleeps a straight 11 hours so I'm not sure what the problem was. So he came to bed with us until he seemed sufficiently relaxed. He wasn't too happy with us when we put him back in his crib after that, but it didn't take him long to go back to sleep.

Very odd. This morning he seems he's usual happy and energetic self.