Mantids will consume any insect. If released in very large numbers they will cause a reduction in the number of pest insects so can be released by the hundreds, in batches throughout the season. Smaller mantids will consume fruit flies, mites, gnats and mosquitoes. Larger mantids consume flying roaches, crickets, some species of grasshopper, some species of beetles, moths, flies and other larger insects. Rarely, mantids will consume small birds. The USDA lists mantids as a beneficial insect.