If anyone's worried about cage aggressive behavior (which honestly, is not a problem with balls) then think about hook training. Every time you are NOT feeding the snakes (handling, cleaning, watering) gently tap the snake on the head with a hook or anything else that is available on hand. The snake quickly learns that it is not being fed. This is particularly useful for the larger snakes. Burms and retics start acting like a dog that thinks it's getting a treat as soon as you start opening their cage. A quick tap on the head, and their feed response is completely extinguished and they can be safely taken out of their cage.

On top of that, there are a number of cons to feeding in a separate tank. Many balls will not eat if they are constantly being moved back and forth. A couple of mine won't eat if I'm watching them or if I've touched them at all any time that day. Plus, while this does not apply to balls, what's more dangerous? A retic that's being fed inside it's cage? Or a retic that's just finished feeding, is still in feeding frenzy mode, and now needs to be moved back into his cage?