I've been experimenting with European Nightcrawlers for my home composting efforts since September with mixed results. The quality of castings is very good, but the quantity has been disappointing compared to red wigglers aka eisenia foetida.
Everything I've read online indicates that European Nightcrawlers do not "ball up" when foraging like red wigglers do. My European Nightcrawlers must not have read those articles because they do actually "ball up" periodically. At first I thought it might be due to something in the bedding that irritated them, but the more I've observed them I'm convinced it's nothing to worry about. My bedding is very neutral and smells like plain old dirt.
Well, I've got to go sort some castings. See you later!