Paul Smiths, NY, Oct 21, 2010 — In general, plants make food from sunlight, and animals fuel themselves by "burning" oxygen. But some animals think outside the box. Curt stager and Martha Foley look at a photosynthetic slug that hijacks the genetic machinery of the algae in its diet, and at a jellyfish that needs no oxygen, burning the alternative fuels of hydrogen and sulphur.