This reminds me of what my dog used to do. He would play with the ball by himself. He had one of those balls that has mini-suctions all over it and they stick to any window, then slowly roll down sticking and unsticking.
He would pick up the ball with his mouth, then throw it at the back door (with glass all over it), then stand there and watch as it rolls down. When it rolls to the bottom, he'll walk up, pick it up, back up, then throw it again... only to watch the show all over again. He will sometimes do this for 15 or 20 minutes. Heh!