Ball python unlike other snakes can be very finicky when it comes to food and tend to imprint on preys making it very hard to switch back.

Very rarely will a BP switch back and forth between preys especially if fed HAMSTERS and/or gerbils.

Now other snakes are different many will eat anything you will toss them without issue.

In other word best to keep a BP on what is readily available, not expensive and not overly aggressive which mean to avoid HAMSTERS and gerbils.