Several years ago my sons and I spent a few days camping in the Selway–Bitterroot Wilderness in Northern Idaho. It’s grizzly bear habitat, but we carried bear spray, kept our campsites clean, and anticipated no major grizzly encounters.

One evening, in the middle of the night, I heard Randy scramble around trying to get out of his sleeping bag. I grabbed my flashlight and turned it on, expecting to see him in the clutches of an enraged grizzly.

There, sitting upright on its haunches and waving its paws in the air was a field mouse about 4” tall. It had Randy’s cap…