You just can't see those things in the dark unless you constantly shine a flashlight on your path. If I wanted to look at the ground I could just stand on the porch. I like to move around while I look at the sky. Squashing nightcrawlers detracts somewhat from the experience.
So I just ruined a perfectly good stroll through the fog, twice. Why don't worms just stay underground where they belong? Stupid nightcrawlers.