I really need your help to organize these ducks

I cherish little canine epiphanies. This morning, Coba made the first glimmerings of connection between what I was asking him to do and the movement of ducks, that crucial first bit of mutual understanding, excitement and willing participation that I needed in order to teach him to herd them.

( A long, rambling explanation, with too much detail, of how this wonderful event came to be. )

And here's the ultimate goal...!