The different species of Termites, which are numerous, build nests of very various forms. Some construct upon the ground a cylindrical turret of clay, about three-quarters of a yard high, surrounded by a projecting conical roof, so as in shape considerably to resemble a mushroom, and composed interiorly of innumerable cells, of various figures and dimensions. Others prefer a more elevated site, and build their nests, which are of different sizes, from that of a hat to that of a sugar-cask, and composed of pieces of wood glued together, amongst the branches of trees, often seventy or eighty feet high. But by far the most curious habitations, are those formed by the Termes bellicosus, a species very common in Guinea, and other parts of the coasts of Africa, of whose proceedings we have a very particular and interesting account in the 71st volume of the Philosophical Transactions.
These nests are formed entirely of clay, and are generally twelve feet high, and broad in proportion; so that when a cluster of them, as is often the case in South America, are placed together, they may be taken for an Indian village, and are in fact sometimes larger than the huts which the natives inhabit. The first process in the erection of these singular structures, is the elevation of two or three turrets of clay, about a foot high, and in shape like a sugar-loaf. These, which seem to be the scaffolds of the future building, rapidly increase in number and height, until at length being widened at the base, joined at the top into one dome, and consolidated all around into a thick wall of clay, they form a building of the size above-mentioned, and of the shape of a haycock, which, when clothed, as it generally soon becomes, with a coating of grass, it at a distance very much resembles. When the building has assumed this its final form, the inner turrets, all but the tops, which project like pinnacles from different parts of it, are removed, and the clay employed over again in other services. It is the lower part alone of the building that is occupied by the inhabitants; the upper portion, or dome, which is very strong and solid, is left empty, serving principally as a defence from the vicissitudes of the weather and the attacks of natural or accidental enemies, and to keep up in the lower part a genial warmth and moisture, necessary to the hatching of the eggs and cherishing of the young ones. The inhabited portion is occupied by the royal chamber, or habitation of the king and queen; the nurseries for the young; the storehouses for food; and innumerable galleries, passages, and empty rooms, arranged according to the following plan:—
In the centre of the building, just under the apex, and nearly on a level with the surface of the ground, is placed the royal chamber, an arched vault of a semi-oval shape, or not unlike a long oven; at first not above an inch long, but enlarged, as the queen increases in bulk, to the length of eight inches or more. In this apartment the king and queen constantly reside, and, from the smallness of the entrances, which are barely large enough to admit their more diminutive subjects, can never possibly come out; thus, like many human potentates, purchasing their sovereignty at the dear rate of the sacrifice of liberty. Immediately adjoining the royal chamber, and surrounding it on all sides to the extent of a foot or more, are placed the royal apartments, an inextricable labyrinth of innumerable arched rooms, of different shapes and sizes, either opening into each other, or communicating by common passages, and intended for the accommodation of the soldiers and attendants, of whom many thousands are always in waiting on their royal master and mistress.
Next to the royal apartments come the nurseries and the magazines. The former are invariably occupied by the eggs and young ones, and, in the infant state of the nest, are placed close to the royal chamber; but when the queen’s augmented size requires a larger apartment, as well as additional rooms for the increased number of attendants wanted to remove her eggs, the small nurseries are taken to pieces, rebuilt at a greater distance, a size larger, and their number increased at the same time. In substance they differ from all the other apartments, being formed of particles of wood, apparently joined together with gums. A collection of these compact, irregular, and small wooden chambers, not one of which is half an inch in width, is inclosed in a common chamber of clay, sometimes as big as a child’s head. Intermixed with the nurseries, lie the magazines, which are chambers of clay, always well stored with provisions, consisting of particles of wood, gums, and the inspissated juices of plants.
These magazines and nurseries, separated by small empty chambers and galleries, which run round them, or communicate from one to the other, are continued on all sides to the outer wall of the building, and reach up within it two-thirds or three-fourths of its height. They do not, however, fill up the whole of the lower part of the hill, but are confined to the sides, leaving an open area in the middle, under the dome, very much resembling the nave of an old cathedral, having its roof supported by two very large Gothic arches, of which those in the middle of the area are sometimes two and three feet high, but as they recede on each side, rapidly diminish, like the arches of aisles in perspective. A flattish roof, imperforated, in order to keep out the wet, if the dome should chance to be injured, covers the top of the assemblage of chambers, nurseries, &c.; and the area, which is a short height above the royal chamber, has a flattish floor, also waterproof, and so contrived as to let any rain, that may chance to get in, run off into the subterraneous passages.
These passages or galleries, which are of an astonishing size, some being above a foot in diameter, perfectly cylindrical, and lined with the same kind of clay of which the hill is composed, served originally, like the catacombs of Paris, as the quarries whence the materials of the building were derived, and afterwards as the grand outlets by which the termites carry on their depredations at a distance from their habitations. They run in a sloping direction, under the bottom of the hill, to the depth of three or four feet, and then branching out horizontally on every side, are carried under ground, near to the surface, to a vast distance. At their entrance into the interior, they communicate with other small galleries, which ascend the outside of the outer shell in a spiral manner, and, winding round the whole body to the top, intersect each other at different heights, opening either immediately in the dome in various places, and into the lower half of the building, or communicating with every part of it by other smaller circular or oval galleries of different diameters. The necessity for the vast size of the main underground galleries, evidently arises from the circumstance of their being the great thoroughfares for the inhabitants, by which they fetch their clay, wood, water, or provision; and their spiral and gradual ascent is requisite for the easy access of the termites, which cannot, but with great difficulty, ascend a perpendicular. To avoid this inconvenience, in the interior vertical parts of the building, a flat pathway, half an inch wide, is often made to wind gradually, like a road cut out of the side of a mountain; by which they travel with great facility up ascents otherwise impracticable. The same ingenious propensity to shorten their labour, seems to have given birth to a contrivance still more extraordinary: this is a kind of bridge, or vast arch, sprung from the floor of the area to the upper apartments at the side of the building, which answers the purpose of a flight of stairs, and must shorten the distance exceedingly in transporting eggs from the royal chambers to the upper nurseries, which in some hills would be four or five feet in the straightest line, and much more if carried through all the winding passages which lead through the inner chambers and apartments. Mr. Smeathman measured one of these bridges, which was half an inch broad, a quarter of an inch thick, and ten inches long, making the size of an elliptic arch of proportionable dimensions, so that it is wonderful it did not fall over, or break by its own weight, before they got it joined to the side of the column above. It was strengthened by a small arch at the bottom, and had a hollow or groove all the length of the upper surface, either made purposely for the greater safety of the passengers, or else worn by frequent treading. It is not the least surprising circumstance attending this bridge, the Gothic arches before spoken of, and in general all the arches of the various galleries and apartments, that, as Mr. Smeathman saw every reason for believing, the termites project them, and do not, as one would have supposed, excavate them.
Consider what incredible labour and diligence, accompanied by the most unremitting activity, and the most unwearied celerity of movement, must be necessary to enable these creatures to accomplish (their size considered) these truly gigantic works. That such diminutive insects, for they are scarcely the fourth of an inch in length, however numerous, should, in the space of three or four years, be able to erect a building twelve feet high, and of proportionable bulk, covered by a vast dome, adorned without by numerous pinnacles and turrets, and sheltering under its ample arch myriads of vaulted apartments, of various dimensions, and constructed of different materials,—that they should moreover excavate, in different directions and at different depths, innumerable subterranean roads or tunnels, some twelve or thirteen inches in diameter, or throw an arch of stone over other roads leading from the metropolis into the adjoining country, to the distance of seven hundred feet,—that they should project and finish the vast interior staircases or bridges, lately described,—and finally, that the millions necessary to execute such Herculean labours, perpetually passing to and fro, should never interrupt and interfere with each other, is a miracle of nature, far exceeding the most boasted works and structures of man; for, did these creatures equal him in size, retaining their usual instincts and activity, their buildings would soar to the astonishing height of half a mile, and their tunnels would expand to a magnificent cylinder of more than three hundred feet in diameter; before which, the pyramids of Egypt, and the aqueducts of Rome, would lose their celebrity, and dwindle into nothing.
The most elevated of the pyramids of Egypt is not more than six hundred feet high, which, setting the average height of man at only five feet, is not more than a hundred and twenty times the height of the workmen employed. Whereas, the nests of the termites being at least twelve feet high, and the insects themselves not exceeding a quarter of an inch in stature, their edifices are upwards of five hundred times the height of the builders; which, supposing them of human dimensions, would be more than half a mile. The shaft of the Roman aqueducts was lofty enough to permit a man on horseback to travel in them.
The first establishment of a colony of termites takes place in the following manner. In the evening, soon after the first tornado, which at the latter end of the dry season proclaims the approach of the ensuing rains, these animals, having attained to their perfect state, in which they are furnished and adorned with two pair of wings, emerge from their clay-built citadels by myriads and myriads, to seek their fortune. Borne on these ample wings, and carried by the wind, they fill the air, entering the houses, extinguishing the lights, and are sometimes driven on board the ships that are not far from the shore. The next morning, they are discovered covering the earth and waters, deprived of the wings which enabled them to avoid their numerous enemies, and which were only calculated to carry them a few hours. They now look like large maggots; and, from the most active, industrious, and rapacious creatures, they are become the most helpless and cowardly beings in nature, the prey of innumerable enemies, to the smallest of which they make not the least resistance. Insects, especially ants, which are always on the hunt for them, leave no place unexplored: birds, reptiles, beasts, and even man himself, look upon this event as their harvest, and, as the reader has been told before, make them their food, so that scarcely a pair in many millions get into a place of safety.
The workers, who are continually prowling about in their covered ways, occasionally meet with one of these pairs, and being impelled by their instinct, pay them homage, and they are elected as it were to be king and queen, or rather founders, of a new colony: all that are not so fortunate, inevitably perish; and, considering the infinite host of their enemies, probably in the course of the following day. The workers, as soon as this election takes place, begin to inclose their new rulers in a small chamber of clay, before described, suited to their size, the entrances to which are only large enough to admit themselves and the neuters, but much too small for the royal pair to pass through;—so that their state of royalty is a state of confinement, and so continues during the remainder of their existence. The female, after this confinement, soon begins to furnish the infant colony with new inhabitants. The care of feeding her and her companion, devolves upon the industrious larvæ, which supply them both with every thing that they want. As she increases in dimensions, they continue to enlarge the cell in which she is detained. When the business of oviposition commences, they take the eggs from her, and deposit them in their nurseries. Her abdomen now begins gradually to extend, till in process of time it is enlarged to fifteen hundred or two thousand times the size of the rest of her body, and her bulk equals that of twenty or thirty thousand workers. This part, often more than three inches in length, is now a vast matrix of eggs, which make long circumvolutions through numberless slender serpentine vessels: it is also remarkable for its peristaltic motion, (in this resembling the female ant; see Gould’s Account of English Ants, p. 22.) which, like the undulations of water, produces a perpetual and successive rise and fall over the whole surface of the abdomen, and occasions a constant extrusion of the eggs, amounting sometimes in old females to sixty in a minute, or eighty thousand and upwards in twenty-four hours. As these females live two years in their perfect state, how astonishing must be the number produced in that time!