For over a year I've been putting Giselle's food inside a feeding cage -- a cage that only she is skinny enough to squeeze into (See http://michigoose.blogspot.com/2008/09/new-frontiers-in-cat-feeding.html). I had to Velcro her food dish to the far corner of the floor because Pumpkin figured out that if he could paw the dish over to the door of the cage, he could stick his head in and eat her dinner.
Over the last year, Pumpkin has lost at least a pound and a half from his high weight of 19.5 pounds. I knew the day would come when he could break into Zellie's feeding cage. Last Thursday morning I was getting dressed when I heard what sounded like the cage being torn apart, and I got out to the kitchen to find a confused-looking Pumpkin inside the cage. Zellie didn't seem upset that he was in there, but he definitely was having a hard time getting back out.