Wolf spiders will eat anything they can catch, even each other. But thanks to an invasive grass, they can now hide from their kin and feast on toads instead. Japanese stiltgrass has spread across the Southeast since it was inadvertently brought to the United States in the 1900s. Recently, ecologists noticed that young American toads were not surviving well where stiltgrass had invaded their forest habitat. At first, they thought fewer insects were living in the grass, meaning less food for the toads. But experiments, reported in Ecology, showed that spiders were hiding out in what John Maerz of the University of Georgia, Athens, described as the “tall shag carpet” of stiltgrass, and they are preying on toads. The study, described yesterday in Entomology Today, shows how an invasive species can restructure ecological relationships.