Though the crawlspace under the house is nowhere near as full of creepy things as I had imagined, the trick to maintaining one's calm down there is never to focus on anything, especially not the corners, where joists and floorboards come together to make a nice home for all sorts of spiders.
While I was down there, I installed a dryer duct between the laundry room and the side of the house. Done.
And to think: For the past year, we've had to stick a flexible dryer duct out the window, rain or shine, every time we've wanted to run the dryer.