The bitter apple spray works on cats too, anything they gnaw and it bugs you, spray it. And since they groom themselves all the time, if they're scratching something like furniture, spray that too and after they scratch it, next time they lick their paws it will taste gross, eventually the weasly little shits will get the picture. I used to have a Maine coon cat cross that thought he was a dog. Only cat I ever got along with.