Knowing the sympathy and affection which the nurses are ever wont to cherish towards the objects of their care, this act of cruelty struck me as something very astonishing and peculiar.
Prompted by curiosity to know the nature of the wounds thus inflicted, I placed upon the palm of my hand one of the wounded ants, and made, by means of a microscope, a careful examination of its injuries. Above and below the abdomen, between the second and third segments, two deep wounds, which met each other in the interior, were plainly to be seen.
Several cases of the kind were afterwards noticed. These were not accidental occurrences, made through efforts to carry the young to places of shelter. Possibly, through inexperience, accidents might happen once in a long time, but to suppose that insects, accustomed to handling their young as the neuters assuredly are, would be likely to make such blunders, is too unreasonable to be entertained. Admitting for argument’s sake that such things might occasionally occur, would successive repetitions be expected? I apprehend not. But on the supposition that a purpose was thereby subserved, the object had in view warrants, it would seem, the means employed for its accomplishment.
What the purpose was it will now be my aim to show. That many animals, tame as well as wild, are wont to destroy disabled and wounded companions, is well established by history. In many instances the destruction is justified to preserve the herd or pack from the close pursuit of enemies. “Instinct or reason,” as Darwin says, “may suggest the expelling an injured companion, lest beasts of prey, including man, should be tempted to follow the troop.”
Audubon, in writing of the wild turkey, so abundant in his day, observes substantially that the old males in their marches often destroy the young by picking the head, but do not venture to disturb the full-grown and vigorous. The feeble and immature being an encumbrance, it is obvious that the watchfulness and attention which they would require, were sympathy and affection the emotions by which the males are actuated, would necessarily retard progress, and lead to the destruction of the entire flock. Instinct or reason here operates for individual and family good.
Granting that instinct or reason does sometimes act for individual and family preservation in the manner described, I am not willing to admit that in every case that may arise in which the weak and disabled are sacrificed, that it is done for the material benefit of the physically able and robust. How the destruction of the weak and nearly-developed ant can result in good to the colony, in view of the fact that not the slightest effort to escape the danger by flight is undertaken, the sole object being the hiding of the young, it is most difficult to conceive.
There seems to be one of two theories, in the writer’s judgment, that will, in anything like a satisfactory manner, account for this strange, abnormal habit upon the part of an insect that has been proverbially distinguished for its kind and affectionate disposition towards the tender beings committed to its trust; either to attribute it to an unwillingness and dislike to see its offspring made the servants of a hostile race or the subjects of ill-treatment and abuse, or to the survival of a habit of the past when its ancestors were a migratory, or nomadic, species.
That a feeling of repugnance does sometimes take possession of animal nature when the objects of parental care and solicitude are, or are about to be, reduced to slavery or confinement, and impels to actions of cruelty, will be patent from what follows:—
A friend, several summers ago, having procured a pair of young robins, placed them in a cage, which he hung from a tree-branch close to his dwelling, where the parent-birds could have an opportunity to feed them. All went well for a few days, when the parents, who had busied themselves in the intervals of feeding in attempts to secure their release, finding their efforts unavailing, flew away, but only to return with something green in their bills, most probably poisonous caterpillars, which they fed to their offspring. A few minutes later and they lay in the bottom of the cage dead, but the parents, as if conscious of what would result, flew away, and never came back.
May it not be that the parents, finding all efforts to restore their young to freedom ineffectual, sought this method of saving them from a life to which death must assuredly be preferable? Instances of like character might be adduced by the hundred, but enough has been written to show that, in the case of Formica flava, an unwillingness to allow the humblest of the colony to be taken into bondage was the motive which prompted the sacrifice.