Why cats rub your leg. A cat rubs up against your leg is partly to make friendly physical contact with you, but there is more to it than that. What the cat is doing is implementing a scent exchange between you and it. There are special sent glands on the temples, sides of the mouth and root of the tail. Without your realizing it, your cat has marked you with its scent from these glands. This makes the cat feel more at home with its human companion. This is achieved by the flank-rubbing element of the greeting, followed by the cat sitting down and 'tasting' us with its tongue by licking the fur it has just rubbed so carefully against us.