Nest of Isodontia auripes, a grass-carrying sphecid wasp that often stocks its nest with paralyzed tree crickets. This nest, stocked with at least a dozen Oecanthus latipennis, was found on the upper surface of a porch rail, beneath a door mat that had been draped over the rail for some time.
For more on Isodontia auripes see http://insects.ummz.lsa.umich.edu/sphecidwasps/Isoauripes.html.