Bees have a just renown as honest and laborious insects; there are, however, some who depart from the right road, and they do not do it by halves.[31] Among Hymenoptera the lazy profess the theory that pollen belongs to all bees, and that stored-up honey does not constitute private property. Therefore, to protest against work and economy, sly methods are employed by a few to utilise as their own private property the resources which Nature has made for all; they adopt the plan of plundering the working insects, and carrying away for themselves the pollen which the others had had the audacity to seek among the flowers.
To arrive at these ends these clever Hymenoptera employ cunning, and endeavour to pose as workers. They place themselves at the approaches to a hive, and when a worker arrives laden with its burden they advance towards it, caress it with their antennæ, take possession of its pollen as if to relieve it of a burden, and then fly away to their own hive.
Others adopt less diplomatic proceedings. Some unite to intrude in a badly-guarded hive, and gorge themselves with the honey to which they have no right. Following up this success, they bring accomplices; a veritable band of brigands is organised, who have no other industry than to seize honey already manufactured in order to fill their own cells. Their audacious enterprises are not always crowned with success; they are repulsed in populous and well-organised hives, but they are successful in the weaker ones. Sometimes they act with violence, and to reduce a swarm they first fall on the queen and kill her with their stings. Disconcerted by her death, the bees allow the pillage of their dwelling, and the cells are robbed from top to bottom. In some cases the deprived proprietors, in their turn carried away by this insanity of rapine, even go over themselves to the assailing party, and carry their own honey to the house of the bandits. Henceforth they unite their fortune to that of the others, and share in their easy and adventurous life.[32]
Bates has given a vivid description of the armies of the South American Foraging Ants (Eciton). They are carnivorous hunters who march in large armies, and are found on the banks of the Amazon, especially in the open campos of Santarem. The Eciton legionis chiefly carry off the mangled larvæ and pupæ of other ants. They will attack the nests of a bulky species of the genus Formica; they lift out the bodies of these ants and tear them in pieces, as they are too large for a single Eciton to carry off, a number of carriers seizing each fragment. They seem to divide into parties, one party excavating and the other carrying away the grains of earth to a distance from the hole just sufficient to prevent them rolling back into it. There is, however, no rigid distribution of labour, the miners sometimes becoming carriers, and then again assuming the office of carrying off the prey. In marching off they form a broad and compact column, sixty or seventy yards in length, those who may be empty-handed assisting heavily-laden comrades. The Eciton drepanophora attacks and carries off all kinds of insects, especially wingless species, such as maggots, caterpillars, larvæ of cockroaches, etc. An eyeless species,[33] the Eciton erratica, rapidly forms covered passages under which to advance, and shows great skill in fitting the keystone to these convex arcades.[34]
Belt has also made some extremely interesting observations on the Ecitons, whom for intelligence he places first among the ants of Central America, and as such at the head of the Articulata.[35]
Expeditions to acquire slaves. — In order to reduce one’s own species to slavery, it seems at first that an intelligence is required as developed as that of Man. It is necessary in fact to attack beings nearly equally well endowed from an intellectual and physical point of view. The enterprise evidently presents every possible difficulty; but in case of success, the result more than compensates for the effort. The master in future need not trouble to work, for he possesses a tool capable of doing everything as well as himself, since by means of language he can easily impress his will on the acts of the other; a domestic animal is only an auxiliary, the slave entirely replaces his owner in every labour.
Several species of ants thus obtain slaves. The best known of these is the Polyergus rufescens. We shall see in another chapter in what way they take advantage of slaves, and what relations they have with them. At present it is only necessary to say how the slaves are obtained. The expeditions organised for this purpose are simply a perfected chase, both by the way in which they are conducted, and by the result to which they are to lead. It is not a question of brutally seizing a prey to be devoured immediately. The captured animal must be carefully managed, carried away alive and in such a condition that it has not yet known a free life, and can accustom itself to new conditions. When the Polyergus or Amazon ants desire to increase their band of slaves, one first remarks extreme excitement in the neighbourhood of the nest. They all come out helter-skelter, but this disorder lasts only for a short time; they soon form in line, and a regular serried column is formed, longer or shorter according to the swarm; it has been found to measure more than five metres long by fifteen centimetres broad. The Amazons advance, often changing their direction like a dog who is seeking a scent: this is exactly what they are doing, they smell the ground with their antennæ in order to recognise traces of the Formica fusca. In this march the eminently republican instinct of the ants comes out. The band has no chief; those who are at the head go forward smelling the ground; this slackens their pace, so that they are passed by those in the ranks behind. Little by little they fall into single file, and this continuing during the whole course of the march, a particular ant may sometimes be at the head of the column, sometimes in the middle, sometimes in the rear. At the end of a longer or shorter period the expedition discovers a scent, which it follows up to the nest of the Formica fusca. The alarm is immediately given in the threatened ant-hill; the approach is announced of a band of slavers, and they all rush out, some to face their terrible adversaries while the others take up the nymphs and eggs in their mandibles and flee in all directions to save as many as possible of their offspring. The small ants endeavour with their burdens to climb to the summits of blades of grass; those who succeed are in safety with the eggs that they carry, for the Amazons do not climb. In the meanwhile a fierce battle is going on in the neighbourhood of the nest between the Formica fusca, who have made a sortie, and the slavers. It is an unequal struggle, because the latter are armed with formidable jaws, strong and sharp, borne by a large head with powerful muscles. The defenders of the nest are seized and placed hors de combat. They flee discouraged, and the assailants force the entry of the dwelling. They then take possession of the larvæ and nymphs and come out again holding them in their mandibles. The Polyergus thus laden flee as fast as possible, escaping as well as they can from the bereaved parents, who endeavour to save their offspring. The band returns to the nest by the same road that it came, although not the shortest, for these insects seem to lack the sense of direction and are guided by smell, so that they have to retrace all the windings of the road. The march is slackened by the weight of the booty ([Fig. 7]), and each travels according to his fancy, without following the regular order of the departure. At last the ants regain their household. The slaves, warned of the return of the victorious army, rush out to meet it and relieve the arrivals of their burdens, some in their zeal even carrying at the same time both the master and his burden. The nymphs transported into the ant-hill are henceforth cared for by their fellow-slaves; the Polyergus do not trouble themselves further.
Wars of the ants. — As sociable as man, the manners of ants present more than one resemblance to his. Slave-hunting expeditions are among these; the wars that these insects undertake also resemble human wars. The causes of the quarrel are of various nature, most often they result from the close proximity of two ant swarms. The rival colonies are always meeting in the same regions and seeking the same material; their mutual rivalry strains their relations. A moment comes when one of them is decidedly in the way of the other. At such a period, which is almost a diplomatic crisis, great excitement is observed in the two camps; there is a continual coming and going. One fine day, as the result of some unknown act, — some mysterious casus belli or declaration of war, — two armies place themselves on the march against each other. They advance in serried ranks. All ants do not follow the same tactics; some throw themselves out in a thicker line, while others form in squares. But as soon as action commences the individual regains his rights. It is a series of duels, of fierce hand-to-hand struggles. Legs are torn away, heads are cut off by strokes of the jaws, abdomens are disembowelled; a terrible fury animates the combatants, and nothing will disturb them from the battle. ([Fig. 8.]) By-and-by victory remains with the fiercest or the strongest; the vanquished draw in, carrying away as far as possible their wounded and their dead. Nothing more is seen on the field of carnage but separated limbs or heads which strew the ground like a multitude of small black points. Often the enmity is not extinguished after a battle, and several defeats are necessary before the weaker swarm is destroyed or forced to emigrate.[36]