I've put cat balls with bells in the girls C & C cage and they just didn't seem to get that overly thrilled about them.......so I decided to try something new with a cat ball.......they love it. I tied a string, jute, twine through two of the holes and hung it up. They just can't seem to leave it alone. If they do chew the twine/jute, not to worry a ball of it is cheap. This is Abby playing with it.