About as scared as I have ever been was once on a deer hunt down in West Tennessee. I was in a shallow draw, and heard a noise just over the top of the draw, perhaps 50 yards away, and the noise was terrifying. It could only be described as a mean, mad, 1200 pound dog with a sore throat letting out a single, hoarse bark. I had never heard the sound before, had no idea what it was, but was convinced that whatever made it was big and mean enough to eat me. After crouching and listening to it twice more, I decided my only chance to get out alive was to try to kill it, whatever it was. I had heard and was comfortable with, about every sound imaginable that could rightly be in that part of the world, and this was something new, unknown, and therefore terrifying. I silently crept and crawled to the lip of the draw, had my old rusty, er, trusty 94 cocked and ready to shoulder, peered out over the floor of the woods, looking, and the sound came again, and movement caught my eye: Up in an old hollow snag about 100 feet in front of me there were TWO of those large, red headed woodpeckers, one on either side of the hollow tree, and they somehow started their pecking together, 180 degrees out of phase with each other and both ended at the same time. I lay there with my head across my arm and shook for a while. Had I heard ONE of them, the sound would have been easily identified and therefore dismissed as harmless. It made me aware of how we depend on prior knowledge and of how the unknown is terrifying.