SmartyKat Catnip with Silvervine Cat Attractant. An exciting blend of attractants guaranteed to entice your cat. Silvervine, a wild-growing herb foraged in the mountains of Japan and China, has a strong natural effect on cats - even on those that typically don't respond to catnip. Extensive testing led us to find the perfect mix. This 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.