SmartyKat® Catnip with Silvervine contains an exciting blend of Silvervine and Catnip. Silvervine, a wild-growing herb foraged in the mountains of Japan and China, has a strong natural effect on cats, even some that don’t respond to catnip. Extensive testing led us to find the perfect blend. Our proprietary blend was created as an ideal alternative for finicky felines who need a little extra excitement! It’s more potent than catnip and as pure as can be! Most cats respond to this blend with a burst of energetic activity followed by a calm mellow period.