Have you ever seen earthworms working? Heard them working?

I did!! The other evening I was out snapping some pictures around the yard...it was just getting to be dusk and I was standing near one of the beds and heard something strange...like something rummaging around in the brush. I knelt down over the bed and there I watched several earthworms crawling around on the surface of the soil grabbing at the left over straw mulch and leaves and pulling them under!!! It was the craziest thing I ever seen! I stuck my finger down and I couldn't believe how lighting fast those worms could move...unreal!