Right--some ball pythons ARE picky, and prefer one prey type over another--but that's species, not age.
I have balls that will eat only rats, and a few that will eat only mice. Eating only rats is NOT an issue. If they have to eat 'only' one species, rats are the ideal.
Besides, the only ball pythons that ever eat rat pinkies are undersized brand new hatchlings. There's no reason to offer a pinky rat to a normal-sized hatchling, much less any older ball python. (Surprised no one else pointed this out).
my ball is 6-8 weeks old and is only 80 grams i got him about a week ago
60+ gram hatchlings, right out of their first shed, can start on fuzzy rats.
Until one has loved an animal a part of one's soul remains unawakened.