Ice worms were found in the ocean at a depth of about 500 meters. They live on a structure called the "hydrate" which , in fact, is a "block" of frozen methane. Family of bacteria live there and feed on hydrocarbon gas. These bacteria attract ice worms as a source of power.
Small pink worms live only two weeks, digging small holes in the ice methane to gain access to the bacteria. Then they multiply and die, leaving their offspring to continue the species.