You should always supervise your baby during tummy time. This is because they may need your help to get out of an unsafe position. They may not yet have enough strength to move their head to the side. If your baby falls asleep during tummy time, you should pick them up and put them in their crib, on their back. Babies should always sleep on their backs until they are masters at rolling over and they choose to roll over and sleep on their tummy. Keep in mind that your baby might shimmy and roll over before you even realize they’re able to do so. For this reason, you should put your baby down on the floor on a mat or blanket that doesn’t bunch up easily.