Cats have much more exacting nutritional requirements than dogs do, so they have to be careful about what they eat. Also, as solitary hunters, their ancestors could afford to eat in their own good time. Dogs, in contrast, are descended from pack-hunting wolves, which evolved to eat quickly so they could grab their share of the kill. Cats also prefer to hide their feces, which would otherwise betray their whereabouts to prey and predators alike, hence their reluctance to use a dirty litter box. Cats are much more sensitive than dogs are to any change in their environment because they are territorial animals that get their sense of security from the place where they live. That’s why cats often try to get back to their owner’s previous home in the first few weeks following a house move.
If they are literally dying of hunger, cats (and dogs) will eat anything available. I’m sure that they don’t mean to cause offense!