A pinky what? Mouse or rat? Pinky rat, maybe, pinky mouse, no way.

Hatchling Ball Pythons can easily eat a good-sized hopper mouse or a rat pup. Pinky mice are much too small and it would take the snake more energy to consume and digest the pinky than the pinky would provide the snake.

How big is the snake? If he's small, say around a foot long or so, try a hopper mouse every 5 days until he sheds a few times, then move up to a small or medium adult mouse every 5 days.

Just watch how his growth rate is. It would be a good investment to get a small scale. If you have a Harbor Freight in your area, they have great digital gram scales for under $30. Wal-Mart also has a nice digital food scale, or you can buy online.