Tried and tested on over 100 domestic cats - it is completely cat-approved. The fish flops and feels very realistic and cats can't seem to resist this. Like catnip, Silvervine is all-natural and non-toxic but Silvervine is much more potent. The cat toys are filled with 100% Silvervine shred, not just a small percentage of Silvervine power and cotton like some other Silvervine toys on the market.