Earthworms belong to the terrestrial animals of Oligochaeta in annelids, with more than 1800 species, especially earthworms. There are 17 species native to the United States and 13 species introduced from Europe, among which L.terrestris is the most common. Also known as pipa bug. Earthworms can be found in almost all soils with suitable humidity and sufficient organic matter in the world. An Australian earthworm can be as long as 3.3 meters (about 1 1 foot).

Earthworm John markham is an invertebrate. Earthworms are about 25 cm (10 inch) long and reddish brown. The reason why it is red is because the blood contains heme. Some earthworms (such as the pale yellow-green earthworms (Allolobophorachlorotica) native to Britain) are green. 0

Earthworms are divided into many segments (up to 150 segments). Each segment has some internal organs (such as excretory organs). Parts 32-37 are slightly thicker, without internode grooves, and slightly lighter in color. During the breeding season, they can secrete sticky substances, form earthworm cocoons and wrap the discharged eggs. The front and rear ends of the earthworm body are tapered, and the tail end is slightly blunt. Earthworms have no visual and auditory organs, but they can feel light and vibration. Feeding on decaying organisms in the soil, eating and swallowing a lot of soil, sand and tiny stone chips. It is estimated that the daily intake and excretion of earthworms are equivalent to their body weight. 0

Earthworms are hermaphroditic, but they need allogeneic fertilization. During mating, two earthworms embrace each other, secrete mucus to make their ventral surfaces stick together, and the sperm discharged by each of them is input into the other's seminal vesicle. After mating, the two individuals separate to form an earthworm cocoon, and the earthworm retreats from the earthworm cocoon. Its body is composed of many similar joints and belongs to annelids. Living in the soil, sleeping during the day, coming out at night, eating rotten organic matter and swallowing it with the soil. It also eats fragments such as stems and leaves of plants. When the earthworm cocoon moves forward to the node 14, the mature eggs fall in, and when it passes the node 9 ~ 10, the sperm of the other side escapes from the seminal vesicle, so that the eggs in the earthworm cocoon are fertilized. Twenty-four hours after mating, the earthworm cocoon breaks out from the head end of the earthworm and stays in the soil. Usually, after 2-4 weeks, tiny larvae emerge from earthworm cocoons and look like adults. Sexually mature after 60 to 90 days, and fully developed after about one year. 0

Earthworms usually stay on the surface of the soil, but in dry weather or winter, they can drill down to a depth of 2 meters (7 feet). There is an Asian species that can climb trees after a rainstorm to prevent drowning. Earthworms are food for many kinds of birds and animals, and indirectly provide food for human beings. Loosening soil is beneficial to ventilation and drainage, which can drag organic matter into dug caves to accelerate decomposition, thus increasing the nutrients needed for plant growth. Earthworms can also be used as bait, so they are commonly called insect fishing.