Moreover, the only enemy that we could discover was the parasitic fly, which never attempts to enter when the hole is closed. However, unmoved by our opinion on the subject, spinolæ spends five or six minutes of her precious time in making the neighborhood of her home quite tidy, and then she fills in the mouth of the nest with a little loose earth before going away to catch her fly. Oxybelus, though she is limited in choice by her small size, can catch a fly in three or four minutes. Bembex is strong enough to take anything that she sees, and she has no preference for one species above another, yet she seldom finds one under twenty or twenty–five minutes. When she comes back nothing of the fly is visible unless it is unusually large, so closely is it held under her body by the second pair of legs. She alights, and scratches away the loose earth at the entrance of the nest with her first legs, and then, as she creeps within, she passes the fly along from the second to the third pair, so that the end of its body, projecting beyond the abdomen of the wasp, is visible for an instant before it is carried inside. Sometimes she drops the fly behind her, and then, turning around, pulls it in with her mandibles. In other cases, where a longer portion of the tunnel has been filled with earth, the fly is left lying on the ground while the wasp clears the way. This offers a favorable opportunity to parasites, especially as the fly is not placed with regard to its safety, but is dropped anywhere. The dirt that is kicked out sometimes covers it so that when the way is clear the careless proprietor must search it out and clean it off before she can store it away. In one instance, in which we had been opening a nest close by, the tunnel was entirely blocked by the loose earth which we had disturbed, and the wasp worked for ten minutes before she cleared a way to her nest. During part of this time she held the fly, but when she realized that it was going to be a long piece of work she laid it down near by. As the wasp enters she sometimes leaves the hole open behind her, but oftener fills it by pushing up earth from below. When she comes out again she throws in a little dirt, and then begins to circle about the place. She seems not quite easy about the nest, however, returning three or four times to scratch earth over the entrance, before finally taking her departure. We opened a good many nests in the course of the summer, and found them all very much alike, much more so than is the case with other species. The entrance tunnel runs in obliquely for from three to five inches below the surface of the ground, and ends in a pocket.