Terrestrial hermit crabs are among the most widespread beach-dwelling organisms with key ecological functions but receive only very limited research attention. Sebastian Steibl demonstrates how physical parameters shape their overall distribution, presents a possible mechanism for their speciation and coexistence and shows for the first time how different human activities can have a major impact on their populations. The author points out that terrestrial hermit crabs, due to their conspicuous behavior to utilize shells, are a good model to study mechanisms of competition and coexistence in natural populations. Furthermore, they are suitable indicator organisms to assess human impact, as they respond differently depending on the type of anthropogenic disturbance. About the Author: Sebastian Steibl is a PhD student at the Institute of Animal Ecology at the University of Bayreuth, Germany. In his actual PhD research, he builds up on the presented work to investigate the architecture as well as functionality of small insular ecosystems and to analyze how different anthropogenic disturbances impact those ecosystem processes.