Oil production from single cells has been in development since the 1980s primarily for the pharmaceutical and neutraceutical industries, but the technology for using microorganisms to convert plant cellular material directly into oil is still undeveloped. The unusual amount of oil extracted from the imported fire ant (Solenopsis sp.) may be an indication of the presence of oleaginous microorganisms or enzymes supporting the digestion of raw sugars. Yield of the ant oil is 16% dry weight and contains most of the fatty acids also found in other biomass resources. Heat of combustion of the ant oil was 133,000 BTU/gal, an amount within the range of reported values for vegetable oil and biodiesel. This investigation also explores the potential source of the oil through stable isotope labeling and offers a unique perspective of a potentially new source of microorganisms or enzymes useful for reducing the cost of producing an alternative fuel. (C) 2013 Elsevier Ltd. All rights reserved.