Dog thinks the moon is a ball.
Well, well. How curious. Of the hundred or so dogs that have passed through my hands for care/training, I've never seen that in a dog before - even with the most ball-crazy ones (which are usually my favourites). Maybe that was because they had just never looked up and noticed the moon, but if they did, or had it pointed out to them (with a "Go fetch!"), then it could
(I suppose) probably look like a whitish ball hanging in the air, to them. Dogs don't usually look up very much without a cue (no natural aerial threats), unless (say) it's a retriever trained to spot birds falling after being shot.
The dog in the video looked like some kind of typical young Welsh collie (sheep-dog), or a cross - sounded like one too - and they tend to be smarter and more observant than the average dog. Ball-crazy dogs usually understand ballistics though, and a stationary object above should not be a ball.