I have been doing earthworm farming as a hobby for 40 years. I experimented with different breeding technologies and fed them with different types of food.
Earthworms are the best gardeners.
They produce the best natural fertilizer.
They are excellent feed for poultry and pigs.
Earthworms are raw material for animal meal, high in protein.
They help us dispose of manure.
They help us dispose of household biological waste.
And they can also help us in the disposal of municipal sludge, as well as in the disposal of mixed municipal waste.