Cat toys with a combination of natural attractants. For livelier play! Silver Vine is a vine that grows in the high, mountainous regions of eastern Asia. It produces a natural and effective cat attractant, that stimulates liverlier play in more cats when compared to Catnip alone. Cats respond more intensely to Silver Vine vs Catnip. The combination of Silver Vine and Catnip is most effective, with more than 90% of cats responding. - Dr. Sebastian Bol, Ph. D., in BMC Veterinary Research. Our bright and sparkly Koi Dangler Cat Toy fascinates cats with the lively bounce of the Koi bait attached to the end of the elastic string. Containing natural yet potent Silver Vine and Catnip attractants, this invigorating toy grabs and holds your cat's attention for livelier playtime and interaction. The versatile wand can be used to tease cats during interactive playtime or can be suctioned to a flat glossy surface for independent play. For more information & research results see hartz.com/cattraction. Hartz.com. Facebook. Instagram. Made in China.