All their industry is expended in the acquisition of captives. The _Polyergus_ avoid introducing into their houses adults who would not become reconciled to the loss of liberty, and would prefer to die rather than work for others. They carry off the larvae of _Formica fusca_ and _Formica cunicularia_. When brought into the ant-hill these larvae are placed in the jaws of slaves of their own species, who care for them; they are born captives, and have neither the regret nor the idea of a free life. Among the Amazons the slaves undertake every labour; it is they who build and who care for the larvae of their masters, as well as those carried away in expeditions. They have also complicated personal services towards the _Polyergus_. They bring them food, lick off the dust from their hairs, clean them, carry them from one place to another, if there is need to emigrate, although they themselves are much smaller. The masters, by force of losing interest in work, lose also their votes when it is a question of taking a resolution concerning the whole colony. The servants act on their own initiative and their own responsibility, direct constructions according to their own ideas, and even in grave concerns, such as emigration, the idle masters do not seem to be consulted. The workers deliberate among themselves, and having come to a decision, proceed to execute it. They transport the household goods, the eggs, the future of the city, and the Amazons who have become its parasites. It is a most curious fact that the slaves should submit to this precarious fate when their masters are absolutely dependent on them. It is just to add that the robust mandibles of the latter may contribute to preserve the position they enjoy.[70] [70] Lubbock has a brief discussion on the relations of Ants to their domestic animals and to their slaves, _Ants, Bees, and Wasps_, chap. iv. CHAPTER V. PROVISION FOR REARING THE YOUNG. THE PRESERVATION OF THE INDIVIDUAL AND THE PRESERVATION OF THE SPECIES--FOODS MANUFACTURED BY THE PARENTS FOR THEIR YOUNG--SPECIES WHICH OBTAIN FOR THEIR LARVAE FOODS MANUFACTURED BY OTHERS--CARCASSES OF ANIMALS STORED UP--PROVISION OF PARALYSED LIVING ANIMALS--THE CAUSE OF THE PARALYSIS--THE SURENESS OF INSTINCT--SIMILAR CASES IN WHICH THE SPECIFIC INSTINCT IS LESS POWERFUL AND INDIVIDUAL INITIATIVE GREATER--GENERA LESS SKILFUL IN THE ART OF PARALYSING VICTIMS.