Filled with a custom blend of tempting catnip and silvervine for twice the cat attractants, plus fun crinkle for enticing sound. Silvervine is an all-natural catnip alternative that cats love, it elicits a similar reaction to catnip, and works for many cats who normally are not affected by catnip. Its high-quality materials and catnip/silvervine blend are pure, pesticide free, and have a high potency.