When I go to pick up Ronan after he wakes up (or when I peak on him) this is how I find him sleeping. He is always rolled over on his tummy, with arms up and hands by his head. It is so cute. Babies are not supposed to sleep on their tummys because of SIDS. But I guess if he is old enough to roll him self over on his tummy he is old enough to sleep on his tummy. I just haven’t seen him roll on his back yet. Though I’m never quick enough to see him roll on his tummy either. So I assume he is capable of doing both.