<i>Caenorhabditis elegans</i> foraging: from natural to laboratory conditions

Foraging theory, the theoretical framework that describes strategies to find and exploit food sources, was originally applied to relatively complex organisms. However, many species face the same challenges while relying on simple sensory inputs and limited cognitive processes. The nematode Caenorhabditis elegans belongs to those species: it lacks vision and hearing, and only has 302 neurons, but it is a cosmopolitan species that can successfully forage in a wide range of conditions. Caenorhabditis elegans also belongs to the narrow list of model species: it is easy to grow in the laboratory, and its molecular and neuronal pathways have been described in extraordinary detail. Its foraging behaviour has also been described with great detail in laboratory conditions, and in the last 20 years, sampling studies have given invaluable insights into the life of the worms in the wild. However, relatively little work has been done to connect these two bodies of work. Here, we review what is known about C. elegans foraging in the laboratory and in the wild and discuss how to unify these results through the lens of behavioural ecology.