Catnip (Nepeta cataria) is a hardy perennial herb attractive to cats. Also known as cat-mint or catnep, it belongs to the mint family. The whole cat family (Felidae) reacts to catnip. These animals will become playful by rolling over, rubbing their faces, extending their claws, and dooing body twists when they smell catnip's pungent odor. It is speculated that the oil from the leaves of catnip excites cats because it contains a chemical called trans-neptlactone, which closely resembles an excretion in a female cat's urine.