I know it's not the common thought on this forum that feeding in a cage can cause aggression, but with corns that have been fed in their cages, I have seen some where just opening the top causes them to go into full feeding mode. Feed them outside their cage, no aggression. Switch to inside the cage, the aggression starts because they get into feeding mode when the top opens. Switch back, and after awhile, the snake no longer goes into feeding mode when the lid is opened. I have not seen any signs of this with my balls and continue to feed them in their cages, but I will never again allow any of my corns to be fed in their cages. As it is, I spent a few minutes dislodging one of my females off my finger tonight (corn) because I haven't been taking her out except to feed. Corns are generally much more aggressive feeders and when they get into that feeding mode, they don't seem to care if it's a mouse or a gloved finger. That is my mistake for not taking her out more because I've had/seen this problem before. It's one of those things which I think is more species/individual dependent. Balls are not the aggressive feeders that corns are and corns will strike and try to eat anything when they are in a feeding response mode. It doesn't always take scent to do it either unfortunately. On the other side of things, I have a couple who are lazy feeders and I could probably feed them anywhere and they would never have an issue. The only ones I've ever seen to respond like that are those with very strong/aggressive feeding responses.