Several years ago my wife and I had a dog with time on her hands and a love-hate attitude regarding our mailman. Anticipating his arrival in front of our house by an hour or so, she would lie on the sofa just inside the front window and wait patiently for his arrival, but at his first step in the direction of our front porch, she would let out a blood curdling howl that did not cease until the menace was safely out of sight.