You can feed an adult ball python mice all their life. Yes, it will take more mice than rats. I have a female a little over 4000 grams thats a mouse feeder. I offer her food every 3 days, 2 to 3 mice if she takes them. sometimes not, and she puts her weight back on quickly after laying eggs. Get a scale and weigh her. This will be your best judge on how much to feed her. Also there are so many keepers out there that keep the hot side very hot. not that it's going to burn the snake, but the snake metabolizes it's food faster, and doesn't get as much out of the food item. I read keepers with temps at 92 to 94, Dr. Scott Stahl (not sure on the spelling) one of the top vets for ball pythons keeps his hot side at 85. I keep my around 88. Why? when all my snakes poop it is digested to the point it should be. Also there are many large breeders that drop the temps on males durning breeding season to around 86 on the hot side, the reason I was told, it's less of a chance for damaging the sperm with these temps, I read so many posts that saids that this is what you need to do, No, It should say, This is what you need to try.This is a hobby with still so much to learn, what works for one, doesn't always work for the other.
Someone might post something after this post and disagree with something in here. I'll read it, using common sense might try it, and could change my mind. nothing is written in stone, which is one of the reasons I enjoy this hobby.