Rats or mice...makes no difference. There have been no studies done (that I've ever heard of) that say what a ball pythons exact nutritional needs are...so how can anyone say one prey item is better than another? Whatever the snake will eat is what's best for it.

You've only had him for two weeks. It can sometimes take longer than that for them to get over the stress of moving to a new home. And the new home itself might be causing stress as well. If it was born at a breeder's and kept in a small hatching tub/juvie tub and then sent to you...and got plunked down in a big glass aquarium, for instance....it might be feeling very insecure and unwilling to put itself in the vulnerable position of eating.

My suggestion is to re-examine it's entire enclosure to make sure he has as much security as possible...and that temps are in the proper range AND consistently held there. (Wrong temps or fluctuating temps can also put them off food) Then wait another week and try again.

Also, be sure to heat the prey all the way through. If you let them thaw at room temp for just an hour or two and then "blast them with a blow dryer" then they may still be pretty cold in the guts, even if the fur/skin feels warm.

Hopper mice may also be way too small for a bp that size. He can VERY easily take full grown mice. The tiny prey might have seemed not worth the energy it would take to eat.