Earthworms experience constant chemical interactions with bacteria, fungi, plants and small invertebrates across soil ecosystems. Even within their tissues, earthworms harbor symbiotic microbes and small animal parasites that trigger internal metabolic responses such as innate immunity. To reveal the fundamental processes that enable animal-microbe symbioses to form and persist, we have to study their metabolic interactions in situ. By combining novel imaging techniques, a team of researchers around Benedikt Geier from the Max Planck Institute for Marine Microbiology (MPIMM) in Bremen, Germany, has now succeeded in imaging the exciting variety of interactions that take place inside the earthworm. This allows us to observe them in a completely new light.