Tiny worms in knots

I dug out a shovel full of dirt from my "lasagna" bed for my students to "observe" a "worm habitat". The bigger worms would move as I broke the soil into clumps, but I was suprised to find in the clums tiny baby worms that were knoted up into little balls. We haven't had a good rain in over a month and I was wondering if that was a way for the tiny ones to conserve moisture during dry spells or if maybe they hatched from their egg and didn't go too far because the dry clay was too hard and deep for them to eat through when they were that small. Sorry I didn't get a picture, but I had to share anyway because I thought it was so interesting.
Tabitha

That was the nursery....