Relatively simple model organisms such as yeast, fruit-flies and the nematode, Caenorhabditis elegans, have proven to be invaluable resources in biological studies. An example is the widespread use of C. elegans to investigate the complex process of ageing. An important issue when interpreting results from these studies is the similarity of the observed C. elegans mortality pattern in the laboratory to that expected in its natural environment. We found that the longevity of C. elegans under more natural conditions is reduced up to 10-fold compared with standard laboratory culture conditions. Additionally, C. elegans mutants that live twice as long as wild-type worms in laboratory conditions typically die sooner than wild-type worms in a natural soil. These results indicate that conclusions regarding extended longevity drawn from standard laboratory assays may not extend to animals in their native environment.