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. [Illustration: FIG. 7.] [Illustration: FIG. 8.] _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]