As time went on we found on the island two other Philanthus colonies, although that is rather too large a word to apply to them, since one consisted of four nests and the other of only two. When we came to excavate the nests of this species we were greatly astonished at the length of the gallery, and not until then did we properly appreciate the industry of these little wasps. It is no small undertaking to follow one of their tunnels for twenty-two inches, even when, as in this case, the greater part of it is parallel to the surface of the ground. We did not find distinct pockets, as the soil was very crumbly and fell in as we worked, but we came upon clumps of bees an inch or so to one side of the gallery and about three inches apart, with larvæ in different stages of development. In one nest we found twenty-six bees in two clumps, some of them half-eaten, and some of them fresh, but all quite dead. We have no doubt that punctatus completely provisions one pocket and closes the opening from it into the gallery, before she starts another, making a series of six or eight independent cells. The provision for one larva is probably twelve or fourteen bees, the capture of which, in good weather, would be a fair day’s work.
That the males do not always stay on in their ancestral home is shown by an observation that we made on the only occasion that we ever saw this species in our garden. Nothing was stirring at half past three o’clock in the afternoon, and we had given up work and started for home, when, in going up an inclined part of the field, we noticed something in motion within a ragged-edged hole which ran obliquely into the ground. It seemed strange that a wasp should be beginning its nest at so late an hour; but a wasp it was, as we could plainly see when we took an attitude sufficiently humble. It was loosening the earth with its mandibles, and then pushing it backward with its hind legs and abdomen. We had scarcely settled down to watching it when a second one of the same species appeared, and with a good deal of fuss and flutter began to dig its hole close by. The spot chosen by this second one proved unsatisfactory, and another beginning was made in a new place. Again something was wrong, nor was a third choice any better. At last, however, the work was started in earnest, and might have been carried to a conclusion if we had not caught the little creature to satisfy a suspicion that had been growing in our minds. Yes, we were right. The worker was not a female making a nest for the rearing of her young, but a male punctatus, preparing a shelter for the night.
In the mean time the first wasp had pushed back such a quantity of earth that the hole was entirely closed, but every few minutes he came backing out to clear the way. At the end of half an hour all became quiet. The door remained closed, and doubtless the wasp was fast asleep. Putting a blade of grass and then an inverted tumbler over the nest, we left him for the night.
On removing the glass at half past seven the next morning, we found the nest open but the wasp not visible. At half past eight the head appeared just inside the hole, the long antennæ twitching now to this side, now to that, as if an inspection were being made. Soon the head came out. The wasp stood for some minutes making a survey, looking to right and left with lively jerks of the body. Then, apparently concluding that the day was not far enough advanced, he came out, whirled around, and ran head-first into the nest. He probably took another nap, for all was quiet until just before ten o’clock, when the antennæ appeared again. The survey was taken as before, first from within and then with the head in view. At last he flew out, and making three circles, each one wider than the last, about the place, flew away. He stayed out all day, and had not returned at half past three in the afternoon; but on going down at half past four we found that he had gone in and closed the door from below.
It is clear, then, that these males do not construct a new lodging every night, but return to the same spot to sleep. Other wasps creep into crevices. We have often found them, in the morning, in the holes of the posts of our cottage porch; but we are glad to be able to put it down to the credit of one male that he has sufficient foresight and industry to provide a sleeping-place, and sufficient intelligence to return to the spot when the declining sun warns him that evening is approaching.
While punctatus was in the height of its activity we found another species, P. ventilabris, taking bees of several genera and species into a ground nest. She also carried her prey with her second pair of legs, and whenever she left her nest she closed the door. She was a shy little thing, and did not approve of our interest in her. At one time, being startled by some movement on our part, she dropped her load and flew away. We placed the bee upon the closed nest, and when she came back with another, she paused and looked at it, took in the one she was carrying, and then returned for number one. This was placed on the threshold while she entered and turned around, and was then pulled in. Some wasps, notably C. ornata and our little tornado, refuse to take in their prey, even if they have caught it themselves, excepting in a regular succession of events; and thus the more reasonable conduct of ventilabris gains in interest.
To the west of Milwaukee, across the valley of the Menominee, rises a sandy hilltop which is a little insect kingdom by itself. Ants of course abound, and the gentle little solitary bees, with their loads of pollen, may be seen everywhere, seeming to melt into the ground, so quickly and quietly do they open their burrows. Here Oxybelus plys her trade of fly-catching, and graceful Ammophila dances with her shadow over the sunny ground, while Cerceris rests in her doorway with an air of leisurely superiority to the vulgar cares of life; and here, one day in early July, a sudden access of energy seemed to strike Aphilanthops frigidus, a wasp which we had found a year before taking in the wingless queens of ants. All at once they were digging everywhere, biting and scratching with great energy, and soon disappearing in the depths of their sandy tunnels. So deep is their primary gallery that even in this easy medium it takes them the best part of a day to get it ready for storing; but once finished it doubtless serves as a home through the season. It has at the entrance a little cup-shaped vestibule where the wasp drops the ant as she enters, running out of sight herself, and then, after she has turned around, coming back to pull it within. This nest is a very difficult one to excavate neatly, as the sand falls at the slightest touch.
A day or two after we had seen frigidus making her residential arrangements, we found twenty-five or thirty within a few feet of each other, working with great ardor at carrying in queens, the doors being left closed or open according to individual judgment. The steadiest workers brought one every forty minutes, scarcely pausing inside the nest, but others made long stays within, leaving the door closed. The ants were carried under the body with all the legs folded around them, but they were heavy things, and were often dropped as the wasp flew across the field, giving opportunities for robbery that were promptly taken advantage of. We picked up one of these ants and placed it in the doorway of a wasp that had just gone in. She came up twice, looked at it, and backed down again; but the third time she first touched it, then seized it and took it below. From another wasp that was just entering we took the ant she had dropped and moved it half an inch away. When she had turned and come up for it, she seemed surprised, came out and looked about, found it and dropped it in the doorway, going in herself to turn around as before. We seized this chance to move it again, and again she came out, found it, took it back, and dropped it. This was repeated five times, but when she took it in for the sixth time, after dropping it, she whirled around and picked it up so quickly that our malice was foiled.