Yesterday I went to the store and brought an everlasting treat ball. I rembered the discussion about small and medium sizes and since one of mine is larger I got the medium. I didn't get two just in case it was a waste of money and they didn't like it. Well, it went over better than Christmas. They both wanted it and fought over it all evening long. So, today I went to the Pet Expo they had in Edison, NJ and found another one there and brought it home. Guess what, they are still fighting and both want the new one and the one I got yesterday is just sitting on the floor all alone. I just cant win! They are both the same size, color and flavor.