OK, this is nothing to do with electronics. But this is rather fascinating. I was in New Zealand last week on holidays with my family. We went to a farm where this old guy was walking around leaning on his walking stick. "Poor guy," I thought. "He can hardly walk". Well, I was soon shown to be wrong when he wrestled a fully-grown sheep onto its back and sheared it.
Before that he had this dog trotting alongside. It looked pretty placid, it rolled onto its back and let the children pat it. As you can see from the video, he wasn't that placid when faced with half a dozen sheep. He didn't bark once, nor did he touch the sheep, but he had them well under control. Also, he did exactly what the farmer told him to do (maybe with one exception).
Apologies for the slightly poor video quality, but this was just a hand-held still/video camera of my daughter's.