Any owner who has a dog that loves tennis balls and who loves to 'chank' them will understand the need for this post. If like me you despair with the amount of useless balls you have lying around then here is the game for you. I seem to get through a lot of them so I decided there had to be more ways to use them once they have given up the ghost! So here is one of my ideas that your dog might enjoy too.
Take a tired old tennis ball, some treats and a sharp knife
Cut a hole in the ball that the treats will be able to fit out of
Stuff with the treats or food that you want to use. Make sure its quite smelly as rubber tennis balls have a strong scent of their own
Then give it to your dog to roll around, pick up and drop and use their paws to get the treats to drop out. If your dog finds this easy peasy then once you have filled with food, tie an old piece of fabric around the ball and let your dog undo and pull that apart to get to the treat dispensing hole.