Ecosystem engineers are organisms that significantly modify their environment, creating or altering habitats for other species. They can be plants, animals, or even microorganisms. For example, beavers build dams that create ponds, which provide habitats for various aquatic and terrestrial species. These changes can enhance biodiversity and influence nutrient cycling within ecosystems. Another example is coral reefs, formed by tiny coral polyps that build calcium carbonate structures, providing shelter and food for numerous marine organisms. Ecosystem engineers play a crucial role in maintaining ecological balance and supporting the overall health of their environments.