During the summer the female wasp remains constantly in the nest, absorbed with family cares. She is occupied in laying eggs and in feeding her progeny, with the active assistance of the workers, or mules, as Réaumur and Charles de Geer call them, because they are unfruitful.
In the interior of the nests you generally find the most perfectly good understanding existing, and the most perfect order, in spite of the warlike instincts of these insects. It is only on rare occasions that this domestic peace is disturbed by the quarrels of male with male or worker with worker; but these combats are not deadly. Never, moreover, has one nest of wasps been known to declare war against another for the purpose of robbing it. "The government of wasps," says M. Victor Rendu, "explains very well the gentleness of their public conduct. Amongst them there are no despots; no one either reigns or governs; each one lives at liberty in a free city, on the sole condition of never being a burden to the state. They all act in concert, without privileges or monopolies, under the influence of a common law—the great law of the public good, from which no one is exempted."[100]
But this model republic is fatally doomed to early destruction. At the approach of winter all the workers, as also the males, perish. Some pregnant females alone hold out against the cold, and get through the winter, to propagate and perpetuate their species. Before dying, these insects destroy all the larvæ which are not hatched at the first approach of cold weather. In spring the females revive, and begin alone the construction of a new nest. They then lay workers' eggs, which are not long in furnishing them a whole regiment of devoted and active assistants. These traits are pretty nearly the same for the different species of wasps, the only difference being in the way in which they build their nests.
Fig. 350.—Exterior of a Wasp's Nest on a branch of a tree.
We have already said that the common wasp makes its nest in the ground. A gallery, of about an inch and a half in diameter, leads to the nest, situated at a depth which varies from six inches to two feet. "It is," says Réaumur, "a small subterranean town, which is not built in the style of ours, but which has a symmetry of its own. The streets and the dwelling-places are regularly distributed. It is even surrounded with walls on all sides. I do not give this name to the side of the hollow in which it is situated; the walls I allude to are only walls of paper, but strong enough, nevertheless, for the uses for which they are intended." Generally, the shape of the outside of a wasp's nest is spherical or oval, sometimes conical. Its diameter is about from twelve to sixteen inches, its surface, which resembles a mass of bivalve shells, has one hole for entrance, and another for exit, just large enough to allow of one single wasp passing in or out at the same time ([Fig. 350]).
Fig. 351.—Interior of a Wasp's Nest, after Réaumur.