An ecosystem engineer is an organism that significantly modifies its environment, creating or maintaining habitats for other species. These organisms can be plants, animals, or even microorganisms. For example, beavers are well-known ecosystem engineers because they build dams that create ponds, which provide habitats for various aquatic and terrestrial species. Ecosystem engineers play a crucial role in biodiversity and ecosystem health. By altering their surroundings, they influence nutrient cycling, water flow, and soil composition. Other examples include coral reefs, which provide structure and habitat in marine environments, and termites, which aerate soil and decompose organic matter.