ricki,
Wot (spelled "what" in the english lauguange)(keystrokes never killed anyone) stress can lead to is death--not always but sometimes. I would say that 3 adult mice once a week is a bit much for a three foot corn. One a week is fine. If you want a big fat snake, purchase a Burmese python. I know a few people that insist on feeding there snakes until the refuse food. In the wild snakes will eat their fill, becuase food may not come along for weeks or more. In captivity snakes are afforded a feeding schedule. This guarantees a healthy animal if all other conditions are satisfied(proper temps and excercise). It is possible for snakes to get FAT. Their instinct for the hunt is still in their brain--and they will over eat if food is available. Unless you are pumping up a gravid female, I would suggest a regular feeding schedule that meets the demands of the size of your snake.