Some snakes switch readily between mice, rats, and ASFs(african soft furred rats), just like some switch readily between live and f/t
Some are more picky. I've heard that adults who are strictly mousers can be a pain, since it requires more than one item per meal feeding mice to an adult bp.
As for nutrition, you don't need to worry about "treats"
Most people feed mice, rats, and/or ASFs to BPs. Some people feed gerbils. Some people feed hamsters. I haven't really heard of any other common snake food items(rabbits, guinea pigs, chickens, etc) having any kind of popularity for ball pythons, mostly due to size.