You love your cat more than anything, but you can't understand why pieces of your furniture have become destroyed due to your cat's incessant scratching. Scratching is a natural, instinctual behavior in cats that serves several important purposes. Cats scratch in order to mark their territory with their scent and shed old cuticle tissue from their claws. The most obvious function of a cat's claws is for defense. Many people opt to declaw cats because they are inside animals.