My guess is you'd find L. terrestris. They like to make permanent burrows. I always find some in plant pots sitting directly on garden soil. I haven't set it up yet, but my thought was to either build a 1 ft. bottomless box directly on soil and fill it up with leaves & some scraps. The worms would burrow directly in the soil and come up into the box for food. Or I could build a much deeper box (2-3 ft.) with a bottom and fill it with soil, compost & leaves. I'd throw in nightcrawlers every time I found them and see what happens in the box. The box with the bottom would obviously be easier to harvest if you wanted to collect worms for fishing.

http://urbanext.illinois.edu/soil/SoilBiology/earthworms.htm