Flukes are flat, leaf-shaped parasites that belong to the class Trematoda. They often live in the bodies of various animals, including fish, mollusks, and mammals. Flukes can be harmful to their hosts, causing diseases and health issues. They have complex life cycles, often requiring multiple hosts to complete their development. These parasites can be found in both freshwater and saltwater environments. Some flukes, like the liver fluke, can infect humans, leading to serious health problems. Understanding flukes is important for preventing infections and managing the health of both wildlife and humans.