The puzzling thing is that acts like this seem to show higher intelligence than, to judge by various experiments, one would think either ants or bees possessed. The results, for instance, of the experiments made by Lord Avebury in this direction, are rather disappointing than otherwise, especially with ants, creatures so far advanced in civilisation, as we may call it, and the ways of man, that they keep both cows and slaves, milking the one and making the others work for them. The cows are represented by little insects called aphides, one species of which we are accustomed to see upon our rose trees, and the milk is a drop of nectar which they exude from the abdomen, upon the ants gently tapping them there with their antennæ. Various kinds of ants milk various kinds of aphides, and some keep them in their nests, where, indeed, they are born, their eggs being tended with the same care as those of the ants themselves. Thus we see amongst ants a creature kept and used regularly for a certain purpose, as domestic animals are amongst ourselves, and this, as far as we know, is unique in the animal world. The aphides, too, belong to a family of insects quite distinct from the Hymenoptera, amongst which the ants are included. Ant-slaves, on the other hand, are ants themselves, though belonging to another species than their masters. The latter raid their nests and carry off, without injury, the larvæ and pupæ, which they afterwards hatch out in their own. These ants, therefore, are born into slavery, so that they do not know their condition, if we could suppose that that would disquiet them, and, moreover, they are not ill-used, but treated in every respect as well as though they belonged to the community in which they have been born. The only thing that makes them slaves is that they work for the ants by whom they have been captured, but this they do _con amore_—ants love working—so that there is no hardship in it. They work, however, in varying degrees, some species of slave-making ants being accustomed to do a certain amount for themselves, whilst others even require to be fed, and are often carried by their slaves, who, of course, do all the regular household business of building, feeding the young, bringing food to the nest, etc., etc. When Huber—the great French observer of ants and bees—placed thirty of this latter kind of slave-making ants in a box, with some of their larvæ and pupæ and a supply of honey, but without any slaves, “more than one half of them died of hunger in less than two days.” The others were languid and without strength, and appeared able to do nothing. Commiserating their condition, Huber at length gave them a slave. “This individual, unassisted, established order, formed a chamber in the earth, gathered together the larvæ, extricated several young ants that were ready to quit the condition of pupæ, and preserved the life of the remaining Amazons,” as Huber calls these slave-raiders, in allusion to their sex.