After a little while a number of entrances into the nest are visible. They are almost invariably sheltered by projecting leaves, which act as porches, so that when the nest is viewed from above, they are almost entirely hidden. Each of these openings runs into one of the main galleries of the nest, and from thence issues a perfect labyrinth of passages.
This, however, is only half the nest, for the galleries and tunnels extend far beneath the surface of the earth, and have sundry enlarged portions or chambers wherein the immature pupæ may lie during their period of helplessness.
Owing to the very loose structure of the upper nest, and the tendency of the earth to fall into the galleries of the lower nest, it is very difficult to obtain a trustworthy view of the interior. Perhaps I may here be allowed to extract a passage from my “Insects at Home,” the description of the nest and its interior having been written almost on the spot:—
“I have, however, succeeded in obtaining an excellent view into the interior of a Wood-ants’ nest, though it was but a short one. Accompanied by my friend Mr. H. J. B. Hancock,[B] I was visiting some remarkably fine Wood-ants’ nests near Bagshot. We took with us a large piece of plate glass, placed it edgewise on the top of an Ant-hill, and, standing one at each side, cut the nest completely in two, leaving the glass almost wholly buried in it.
[B] Now Sir Henry J. Burford Hancock, Chief Justice of Gibraltar.
“After the expiration of a few weeks, during which time the ants could repair damages, we returned to the spot, and, with a spade, removed one side of the nest as far as the glass, which then served as a window through which we could look into the nest. It was really a wonderful sight.
“The Ant-hill was honeycombed into passages and cells, in all of which the inhabitants were hurriedly running about, being alarmed at the unwonted admission of light into their dwellings. In some of the chambers the pupæ were treasured, and these chambers were continually entered by Ants, which picked up the helpless pupæ, and carried them to other parts of the nest where the unwelcome light had not shown itself.
“Unfortunately this view lasted only a short time. Owing to the partial decomposition of the vegetable substances of which the Ants’ nest is made, the interior is always hot and always moist. Now, the day on which we visited the nest happened to be a cold one, and, in consequence, the moisture of the nest was rapidly condensed on the inner surface of the glass, and in a few minutes completely hid the nest from view, leaving me only time to make a rapid sketch. Unfortunately some one discovered the plate of glass and stole it.
“Next time that I examine a Wood-ants’ nest, I shall take care to insert the glass exactly east and west, and shall open its southern side towards noon on a hot sunshiny day, so that the rays of the sun may warm the glass and prevent evaporation.”
Many other creatures make subterranean dwellings, but the Wood-ant is remarkable for possessing a double dwelling, the two portions communicating with each other, and capable of being used according to the degree of heat required.