INNER PACKS OF 4Â CATNIP + SILVERVINE : Some cats LOVE catnip, but not all cats are affected by it. To solve this problem we developed our own unique blend of catnip and silvervine. Silvervine is a non-toxic, all natural catnip alternative that many cats actually prefer. This potent stimulant elicits a similar reaction to catnip, and is both safe and fun. UNIQUE DESIGN : Mad Toys & Tunnels come in a wide variety of unique, silly, playful designs that are unlike any other Toys & Tunnels. These wild and wacky toys are designed to be fun for both cats and their owners. Mad Toys & Tunnels are perfect for posting photos with your celebrity cat, but even better for playtime! MIXED MATERIALS : Mad Toys & Tunnels are made of soft, high-quality plush with fun accents such as string, crinkle, embroidery and, of course, our custom blend of catnip and silvervine! Ideal for tossing, batting, kicking, and cuddling.