I just got back from the LFS with a single serving of live black worms.
When I put them in the tank I was amazed to see a few "get away" by wiggling
into the substrate. Not sure why I was so amazed to see a worm burrow into
sand but I was.

Now I am wondering:
- can they survive in my laterite/fluorite/black sand substrate mixture?
- Will they ever come back out for a little stroll in the light or dark?
- Will they reproduce?
- Is it good for the tank/plants like in a backyard garden?
- Are there bad and good worms for aquaria?
- Is there an easy way to harvest worms for feeding similar to the way brine
shrimp are?

Any one have any experience keeping worms in their aquariums and care to
enlighten?