Dude, I just bought 6 "cups" of red worms from the baitshop. Your best bet is to get a 5 gal. bucket and toss in all your coffee grounds, tea bags, egg shells, rabbit shit etc. THEN put the worms in that. Small worm farm for composting.
There is only just enough dirt in those cups to keep em alive for a bit. Besides, you want worm castings, not dirt. Worm castings are whats left after the worms pass the oganic matter thru thier system (Poop)
I'm new to this, I have just last week started mine. there is a way to collect the castings, But I'm not there yet. I put about 300 worms in mine, and I figure that by next spring, I'll be ready to collect the castings. It is FUCKIN' WELL WORTH the effort because worm castings are REALLY high dollar in the stores. It would cost a fortune to use alot of worm castings on any kind of grow bigger than 10 plants. Even then, I aint paying that kind of money when I can start a couple of 5 gal buckets of compost and worms.
Initially, I put a few scoops of horse manure/soil in the buckets (Rabbit poo would be good too). , along with the items listed above. I read that they like all sorts of organic matter like newspaper strips (No colored ink), and vegetable matter. I then empty my coffee filter, tea bags etc in there. I'll give it the winter for the worms to convert all that.
We'll see what happens.