Hydrothermal vents host specialised animal species that rely on vent fluid emission for surviving. A large number feed on chemoautotrophic microorganisms (which produce their own energy with 'chemistry') or heterotrophic (which do not produce their own energy) similarly to grazers who feed on plants on land. Ohters are carnivorous and feed on smaller animals. Jozée Sarrazin, researcher and head of the deep-sea lab at Ifremer, explains how life thrives at vents.