Amoeboids are a type of single-celled organism that belong to the group of protists. They are characterized by their ability to change shape, primarily through the extension and retraction of their cell membrane, forming structures called pseudopodia. These extensions help amoeboids move and capture food, such as bacteria and other small particles. Common examples of amoeboids include Amoeba proteus and Entamoeba histolytica. They can be found in various environments, including freshwater, soil, and even inside the bodies of other organisms. Amoeboids play a crucial role in ecosystems by contributing to nutrient cycling and serving as a food source for larger organisms.