Earthworms, belonging to the subclass Lumbricina, are segmented invertebrates found in moist soil environments. They are crucial for soil health, aerating it and enriching it with nutrients through their waste. Earthworms exhibit a cylindrical, elongated body and possess a specialized structure called the clitellum used for reproduction.

Lumbricina, commonly known as earthworms, are found natively across a wide range of regions globally. They are indigenous to Europe, but have since been introduced to many other parts of the world, including North America, Asia, Africa, and Australia. Their natural range includes temperate zones, where they thrive in moist, fertile soils.

Earthworms typically inhabit moist, nutrient-rich soils. They prefer environments with a neutral to slightly acidic pH and are commonly found in gardens, agricultural fields, forests, and grasslands. They require sufficient moisture to survive and are most active in environments where the soil is not too dry or waterlogged.

Earthworms play a vital role in soil ecosystems. They are detritivores, feeding on decomposing organic matter, which they convert into valuable nutrients that enrich the soil. Their burrowing activity aerates the soil, improving water infiltration and root penetration. This makes them crucial for soil health and fertility. Different species of earthworms may vary in their depth of burrowing and soil preference, with some adapted to surface litter while others thrive deeper underground.