I feed mine in their cages. I used to feed them out of them when I first started getting into snakes, but when I got my boa I was told to be sure to feed him in his cage. You don't want a large snake to assume being taken out of the cage means feeding time. It never made a difference with my corns or my ball python. But since it takes the ball about 45 mins to eat, feeding in the cage was a great alternative. As far as I understand (from other reptiles) it's the young ones that have the greatest risk of impaction, older ones have larger digestive systems so particles such as aspen can pass through easier. I keep my hatchlings on paper towels though, it makes it easy for them and for me. My others all are fed in their cages, if I have a prekilled mouse I will hand it to them wherever they happen to be sitting, but if it's frozen thawed, and therefore wet, I make sure to put it on top of something so that it does not get aspen all over it. I could offer them their food in little 2.5 quart tubs, but for now what I am doing works.