If he does wander a lot, there is probably a husbandry issue.

I would downgrade him to a small rat, medium rats are most likely too large. My female who is about 4 feet and almost two years old eats medium rats, I can't see a 2 1/2 foot snake eating one of those. Try a small rat weekly, I feel that snakes need to eat every 7-10 days at the most. It will not mess him up either, I'm pretty sure he'll be fine if he's a strong eater.

Check back on your husbandry though, humidity, temps, hides, etc.