Discusses research being done on Caenorhabditis elegans (C. elegans) as a model for innate immunity. Reference to studies by D.H. Kim and G.V. Mallo, published in the 2002 issue of 'Science'; Progeny of mutagenized worms which had been exposed to Pseudomona aeruginosa; Method of looking for C. elegnas genes that are upregulated in response to infection by the bacterium Serratia marcescens.