My cat Tidus likes to chew on things, like a dog. Nothing that is dangerous, like cords. He doesn't eat the stuff he chews on, just chews in it, like gum. He chews on the wooden knobs of my TV stand, which I don't mind, but there's no more knob left so I'm curious if there are any sort of toys or things that he can chew on to stay content? I don't want to stop him from doing it because he enjoys it, so I'm curious.