BATTLE GROUND, Wash.—Sue Foster knew what she needed to do when her border collie, Taff, was expelled from puppy school for herding the black Labs into a corner.
She rented some sheep.
Then she bought another border collie and rented some grazing land. Then she bought some sheep of her own. And a third border collie. Now, like the old lady who swallowed the fly, Ms. Foster keeps a llama to chase off the coyotes that threaten the lambs that go to market to finance the sheep that entertain her dogs.