Very cool photos.. I always enjoyed watching them stretch out in the yard from burrow to burrow connecting. I guess they were mating, but this was when I was a kid. When you would get too close they would break free and snap back like rubber bands.
Is that why rotting leaves have intact holes where the leaf veins are still intact, worms rasp off leaf particles?
I buy nightcrawlers to release in my garden early spring when it's cool and wet. They thrive under the shrubs where I cant mow and lots of dead organic matter builds up, but the soil quality is great now and so are the shrubs!