Beneath our feet lies one of the most biodiverse habitats imaginable – the soil. These highly active underground microbial communities are vital to ecosystem health; they cycle nutrients, form soil structure, and decompose organic matter, among many other functions. The type of microbes that colonise soil is determined by the local plant community and climatic variables, both of which are rapidly changing due to human activity. In a recent study, Dr Carl Rosier of the University of Delaware has explored how urban development disturbs the environmental cycles that influence the types of microbes found in various soil habitats.