Scratching is considered a normal behavior in cats. Scratching things is an inherited trait and cats do it instinctively, but it is also learned from their mother early on in life. Cats scratch in order to leave a visual and olfactory (i.e. smell) territorial marker. Their scent comes from sweat glands located in their paws. To a lesser extent, they also scratch in order to condition and trim their claws, and to provide muscle toning