The KONG Naturals Crinkle Ball w/ Feathers is designed specifically to cater to the innate hunting instincts of your pet. The crinkle sound is immediately curious, and exercise and entertainment are provided by the mixture of natural fur, feathers and catnip. These toys are designed to cater to the indoor cat's natural instincts. KONG Naturals are cat toys that are ecologically responsible. Natural, renewable resources include the materials and dyes used.