Cats do bite cardboard boxes to grind their teeth. Many times people think that cats only sharpen their claws by scratching, often ignoring the cat’s need for teeth grinding. However, in fact, cats start to change their teeth when they are 6 months old. When cats can’t find tools to grind their teeth, they will choose paper shells to bite, because corrugated paper can not only meet the cat’s teeth grinding needs, but also keep the cat warm. At this time, if the owner does not want the cat to leave paper scraps all over the floor of the house, Then you need to buy some catnip or cat-specific peppermint sticks to relieve your cat’s tooth itching.