Another theory, commonly used to explain why cats are scratching around their bowls, is that felines bury their leftovers to come back and continue. However, this is false because felines are not scavengers. They typically feed on as much of a carcass as they can eat in one meal after which they stop. Felines, including house cats, have a very strong sense of smell that can detect food that is not fresh. Their survival instinct will keep them away from food that is not fresh so that they do not get sick.