When offering frozen thawed, make sure you heat up the rodent. (putting it in a ziplock bag and floating it in hot water, or using a blow dryer on the hot setting) ball pythons use their heat pits to locate prey and a lot of time if you don't give them prey that's the right temperature they can't 'see' it and don't recognize it as food. Usually you can quit doing this after a while once they're used to eating frozen thawed prey.