all living things need energy to survive, move, grow, and reproduce. some can get energy from the environment without help from other living things: these are called producers, or autotrophs. plants, algae, and some bacteria, a group of producers called photoautotrophs, use the sun's light for energy. when producers use light to make and store organic compounds, this is called photosynthesis. some other producers, called chemoautotrophs, get energy from chemicals that come out of the ocean floor in hydrothermal vents. other living things get their energy from organic compounds: these are called consumers, or heterotrophs. animals, fungi, most bacteria, and most protists are consumers. consumers can eat other living things or dead material.