We bought 2 of these for our 4 cats.  One of them loved it so much that when we had to let him go due to cancer, we had him laid to rest with one of the balls.  The other cats love to bat it around and run with it in their mouths.  If you squeeze it tight it will make noise that cats love as it returns to its shape.  Just be cautious of the overzealous kitty that bites off a chunk of the foil.  If swallowed it can cause some serious damage.  I used to work at a vets office as a tech and saw one cat that needed surgery from one of these.  Use under… read full review »