Grylloblatta campodeiformis Walker were collected from a site in the Alberta Rocky Mountains at an altitude of 1300 m. The gut contents in the autumn consist almost entirely of arthropods. Dominant among these was a tipulid fly, equally typical of the cold, montane habitat as Grylloblatta itself. In the laboratory, G. campodeiformis adults eat only live or recently killed animal prey, and neither adults nor larvae grow without animal food. Prey is detected by the antennae and then seized by the mandibles. Five types of sensilla, all of which are probably involved in prey identification, are described from the antennae and palpi.