We have a 3 year old rag doll, a 16 week old rescue kitten (and an 11 year old lab but he's not really part of this). Whenever we feed them (in separate rooms), the kitten eats his pouch and runs into the other room to steal the rag doll's food. At the same time, the rag doll goes into the other room to steal the kitten's food (which has already gone by then).
So the kitten (unless we keep the doors shut, which they are now with the cats either side miaowing at each other and trying to get in / out) eats the cat food and ends up with a bit of a dodgy belly and the big cat misses out on food.
Kitten will also eat the dog's food if the dog doesn't eat it all first (which he usually does as he is a labrador).
So why do they do this? Is little one just greedy? Is big one just neurotic? (big one has always been a bit strange even before the arrival of shed kitten)