Cat toys with a combination of natural attractants. For livelier play! Swat play pattern. 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 livelier 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. Sebastiaan Bol, Ph.D., in BMC Veterinary Research. Our sweet and lovable wide-eyed Macaron Mice Cat Toys are a delightful way to nurture your cat's basic swatting and hunting instincts. Soft and plush, don't be surprised if your cat hugs and kicks them as well. Containing natural yet potent Silver Vine and Catnip attractants, these captivating toys grab and hold your cat's attention for livelier playtime fun.