Honey-making Ants.—These ants are found in Texas and New Mexico. Their remarkable habits have been observed by Captain Fleeson, who communicated his observations to Mr. Darwin.
The community consists of three distinct kinds of ants, which appear to belong to two distinct genera. These are:
I. Yellow workers; nursers and feeders of II.
II. Yellow honey-makers; sole function to secrete a kind of honey in their large globose abdomens, on which the other ants are supposed to feed. They never quit the nest, and are fed and tended by I.
III. Black workers; guards and purveyors, which surround the nest as sentinels, and also forage for the food required for I. They are much larger and stronger than either I or II, and are provided with very formidable mandibles.
The nest is in the form of an absolutely perfect square, of which each side measures from four to five feet, and the surface of which is kept quite unbroken save at two points, at each of which there is a very minute hole or entrance. One of these minute holes occurs near the west side of the square, and the other near the southeast corner; for it must be remarked that the square is always built with precise reference to the points of the compass, in such a way that one side faces due north, and consequently the others due south, east, and west. These boundaries are rendered very conspicuous by the guard of black workers or soldiers (III), which continuously parade round three of the sides in a close double line of defense, moving in opposite directions. This sentry-path occupies the north, east, and west boundaries, the south side of the square being left open; but, if an enemy approaches on this or any other side, a number of the guards leave their stations and sally forth to face the foe, raising themselves on their hind legs on meeting the enemy, and moving their large mandibles in defiance. After tearing the enemy to pieces the guards return to their places in the line of defense, their object in destroying any insect or other small intruders being defense of the encampment, and not the obtaining of food.
The southern side of the square encampment, or rather fortress, is left open as just described in order to admit of a free entry of supplies. While some of the black workers are on duty as, another and larger division are engaged on duty as purveyors. These enter and leave the quadrangle by its southwest corner in a double line (one laden and the other not), which follows exactly the diagonal of the square to its central point, where all the booty, consisting of flowers and aromatic leaves, is deposited in a heap. Passing from this central heap to the entrance at the southeast corner of the quadrangle, and therefore occupying the other semi-diagonal of the square, there is another double line of workers constantly engaged in carrying the booty from the central deposit into the storehouses below-ground. These workers are exclusively composed of Class II, whose whole life