Nematodes are microscopic, worm-like organisms that live in soil and can be beneficial or harmful to plants. Beneficial nematodes help control pests by preying on harmful insects, while harmful nematodes, known as plant-parasitic nematodes, feed on plant roots, causing damage and reducing crop yields. Nematodes play an important role in the soil ecosystem by contributing to nutrient cycling and regulating pest populations, making them a key element in integrated pest management (IPM).