I just scanned over a feeding nightcrawlers to your fish and coral topic on another forum. Not for sure of this or not at this time, but it does spark my interest. Enough that I just watched a video of an earthworm eating a banana. Before I thought they just ate dirt. The OP cuts up the worm into small pieces and feeds his tank. He is happy with the results. I guess if you could control what the nightcrawler consumes, and make it beneficial to your livestock it might just be tool in the arsenal. But yuck!