Species that exploit transient food patches must both effectively utilize such food sources and colonize new patches. The timing and rate of dispersal from existing patches and adaptations that aid dispersal are therefore crucial. Currently, no system exists in which dispersal has been investigated at both the ecological and genetic levels. The extensively studied model nematode Caenorhabditis elegans is potentially such a system. Dispersal between food patches in C. elegans has been found to be related to polymorphism in the npr-1 gene, which regulates the tendency of worms to aggregate on food. Here I show that this non-dauer larval dispersal is affected by various environmental variables and that variation is not fully explained by differences in aggregation behavior. Quantitative trait loci mapping identifies candidate genomic regions, separate to npr-1, which affect variation in dispersal between two isolates. These data suggest that the ecology of C. elegans is more complex than previously thought, but indicate that it is experimentally tractable.