There are more than 20 kinds of earthworms used for breeding, but the most common species in our country are Daping No. 2, North Star No. 2, Chibi Aisheng earthworms, red earthworms, and the ring of hairy genus earthworms and so on.

The stocking density of earthworms: if it is within 1 month of age young earthworms, 30,000 to 40,000 per square meter; if it is 1 to 5 months of age earthworms, 1,50,000 to 20,000 per square meter; if it is 1, 5 months of age to adult earthworms, 5,000 to 10,000 per square meter.