We use only top quality utilized natural North American catnip for GiGwi refillable catnip toys. These toys have a special fastener, so that fresh catnip teabags can be added again and again – to last all your cats nine lives. Catnip is a natural, non-adicting herb that encourages playful behaviour for about 70% of cats, which have an inherited gene that compels them to respond to catnip.