Earthworms' bodies are round and long, and consist of many similar ring-shaped joints. Earthworms crawl on rough cardboard and can hear a slight rustle, which is the sound made by the friction between bristles on the surface of earthworms and cardboard. Bristles play a role in supporting and fixing the body during exercise. When the earthworm is on the glass plate, it can only see its body crawling, getting thicker and thinner, but it can't move forward. This is because the glass surface is smooth, and friction bristles cannot fix and support the body. Bristles help exercise. Earthworms (autumn sounds) invertebrates, annelids, oligochaetes. There are more than 2500 kinds. There are about 100 species in China. Giant earthworms and burrowing earthworms are common in many places. The body is long cylindrical, about 30 cm long, and consists of more than 70 ~ 100 segments. Except for the 1 segment and the last 1 ~ 2 segment, there are dozens to hundreds of annular bristles on each segment. The genital belt is annular, and there are no bristles on 14 ~ 16 nodes, but only 1 female genital foramen (in the center of 14 nodes). 18 segment has 1 pair of male reproductive pores on the ventral side. There are three pairs of seminal vesicle holes on both sides of the 6th ~ 7th, 7th ~ 8th and 8th ~ 9th intersegmental sulcus in the front of the body, and the ring centers are located at 7th, 9th, 12 and 13. There are no large renal ducts, but there are many small renal ducts. Androgyny, allofertilization. There are 1 ~ 3 eggs laid in the earthworm cocoon (egg bag), fertilized in the earthworm cocoon and hatched about 1 month. Feeding on soil rich in humus. I like to go out at night or after rain. It has a certain effect on improving soil. The body is rich in protein, free of fat and cholesterol, edible, and can also be used as bait for poultry or fish. Chinese medicine uses whole worms (earthworms) as medicine. Clinically, lumbricus has a certain effect on healing wounds and eliminating ureteral calculi. Because the body contains a variety of special enzymes, it can decompose organic waste and help solve the problem of environmental pollution. In recent years, earthworms can absorb trace heavy metals in soil, such as mercury, lead, cadmium, etc., and serve as monitoring animals for heavy metal pollution in soil.