No, catnip toys are not bad for cats. In fact most cats adore catnip! But a cat’s response to catnip is genetic, and around 20-30 percent of cats show no response at all to this herb. If your cat isn’t affected by catnip then there’s no point buying them these toys. It’s also worth bearing in mind that kittens don’t react to catnip until they’re around six months old. The scent of catnip also fades over time, so you might decide to keep these toys in a ziploc bag between play sessions.