Data for: A double edged sword: predation risk effects of a non-native species that acts as predator and prey

This data explores how a non-native species, the crab <i>Hemigrapsus sanguineus</i> that can act as a predator to the native prey and prey of the resident predator, impacts the risk responses of <i>Nucella lapillus</i>, a native snail, to its resident predator, <i>Carcinus maenas</i>.