Who wouldn't love our wacky Petlinks Love Birds This Safari Collection duo is ready to spread joy, with burlap, plush, feathers, rope and filled with HappyNip which is an exciting blend of silver vine and catnip. Silver vine, 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. After extensive testing to find the perfect blend, HappyNip was created as an ideal alternative for finicky felines who need a little extra excitement! HappyNip is more potent than catnip and as pure as can be! Most cats respond to catnip with a burst of energetic activity followed by a perfectly calm mellow period. Our catnip is produced without chemicals or pesticides and is grown on our own catnip farms.