I feed my snake in his enclosure, and I've never had a problem with him mistaking my hand for a mouse, or thinking it's feeding time when it's not. I think the only way this would be a problem is if the only time you opened your snakes enclosure is to feed it. I open my snake's enclosure and stick my hand down there at least once a day (to change water) and usually more, to check the temps on the thermometer, to do any cleaning that is needed, and to handle him now and then of course. I think he is very used to the sound of his enclosure being opened and maybe even used to my big ugly hand messing around with things. The only time he has a feeding response is when he smells/sees a nice mouse/rat dangled in front of him.