ive noticed that too. my corn is like my stress releiver. after only getting one or two of my ball pythons to eat i can always count on that little corn to eat its pinkies.
i saw kathy love talk about corns at the first reptile expo i ever went to. she had a picture of a corn that had actually eaten itself. it looked like it had eaten about half of its body. the snake didnt live, but thats a very good example of their feeding response.