Humans can't drive hogs anywhere they don't want to go, but a good stock dog can very quickly give them an attitude ajustment that makes them decide that was where they wanted to go after all. I've seen a collie dog bring an old sow out of a standing corn field and put her right back through the hole in the fence where she got out. We had run her and several others right past that hole several times before we called the stray collie mix and the rat terrier dogs out to the field. The collie would clamp down on their ears, and the rat terrier would stay behind making ham sandwiches. Those hogs knew exactly where they were supposed to go.