DS is a pro at rolling from his back to his stomach. He will do it within moments of being placed on the floor. He can hold a seated position when placed in a sitting position and will try to scoot along. He does the full baby push up on his stomach with his weight supported on his hands and tries to swim on his stomach. However; he simply will not try to roll from his stomach to his back. He will just dig his face into the ground and cry when he gets tired.
Any ideas on how to encourage rolling from front to back?