We examined how diverse communities of carabid beetles and crickets in a perennial hayfield respond to seed availability numerically and in their feeding behavior. Although there were 3 distinct insect communities identified over the diel cycle, these communities were similar in plots supplemented with Setaria viridis (L.) P. Beauv. seeds and untreated plots. Gryllus pennsylvanicus Burmeister consumed plant material more frequently and ate more food in the fields with greater seed availability. However, they consumed prey with equal frequency in the 2 treatments. Allonemobius sp. consumed food less frequently than G. pennsylvanicus, and their diet was unaffected by seed availability. Availability of nonprey food resources may not affect soil insect communities in the short term, but some omnivores are quick to alter their diet to exploit nonprey resources.