INSECT PARENTHOOD

“There can be few people alive who have not remarked on occasion that men are the creatures of circumstances. But it is one thing to state a belief of this sort in some incidental application, and quite another to realise it completely.”—H. G. Wells.

This statement of Mr. Wells that I have placed at the head of the chapter will explain the reason why I find it necessary to go back to the grey primeval dawn of life to start my inquiry into motherhood. I want to establish that the instinct of caring for the young is not fixed, that it does not always develop in the same way or in the same parent, but rather that it is a quality, fluid and of indeterminate possibilities, that can be set and shaped by the conditions of life as wax is shaped by a mould. And I know no other way to make this clear. The few scattered facts that I have been able to gather together tell the miracles of the parental instinct. They must, I think, teach us humility. Let us throw aside the garments of conceit and false learning, and recognise that in reality we know almost nothing about anything, if things are probed to the bottom.

In the widest treatment of the maternal instinct it will not suffice to narrow our attention to the function of human motherhood, or to take up our study of the conditions relating to the mother and the child as we find them amongst us to-day. Were I to do this and to attempt at[60] once to bring forward my own views, with the reforms that I wish for in this matter, my work would be as a building without a firm foundation, more or less uncertain, and for this reason valueless.

To get a proper grip of all that is here concerned we must understand that the maternal instinct is the deepest and strongest instinct in woman. It is in the emotions and actions either directly arising from or connected with motherhood that we find the real difference between the sexes. In its essence the parental instinct belongs to woman alone. The male may be infected with its energy—we witness this among birds, as well as in humbler animals, where the duties of caring for offspring are shared and, in some cases, carried out by the male alone; but man possesses, as yet, its faint analogy only. It is the most primary of all women’s qualities.[9]

Now, why is this? Why is woman’s being so much more strongly infected with motherhood than the man’s with fatherhood?

It is a question not so readily to be answered as it might appear. If we find the explanation in the intimate connection between the mother and the child we have not, I think, exhausted the matter. We must not forget that other questions remain behind unanswered, all centring round the one question to which an adequate answer is so difficult to find: How has this arisen? The fact has to be explained that the sharp separation in the parental impulse and the parental duties, so strong amongst us, has not always existed; that there are many examples in the history of life which show an exactly opposite condition.

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To find the clue it will thus be necessary to turn our attention to the earlier stages of life where, in particular among insects, reptiles, fishes, and birds, we find the widest possible range of difference in the expression of the parental instinct and the most varied relations existing between parents and offspring. Here indeed, among these pre-human parents, we can study the maternal instinct in the making. There are many new and strange facts for us to learn.

I know well the dangers of such an inquiry. To many, who will allow its interest, it will yet appear as being profitless. There is perhaps some justification for this view. Certainly any attempt to establish the conditions of human motherhood from examples in natural history must be far from conclusive. All comparisons of our own habits and impulses with their earlier expression as we see them in the animals are somewhat unsatisfactory. The lines on which human motherhood has developed and the conditions which have so largely helped to shape its expression, differ vastly from many of the other needs and circumstances which govern the activities of parents in the lower forms of life. Chief among these differences is the more complex character of the human brain, which is correlated with the far greater length of time that the human infant is dependent on its mother.

Yet, allowing for all this difference, I believe that there is much for us to learn from the life-histories of these pre-human parents. At least we find wonderful agreement prevailing between the conduct which we think reason dictates to us and that which we hold instinct dictates to the animals. And the question will be forced upon us: How far back in the record of life did the fierce mother-instinct[62] exist? We shall find many unheeded examples, alike of its operation and of its failure to operate, which, if we consider them, in the light they may possibly cast forward on our own problems, will not fail to bring us to some unexpected conclusions. Life is full of surprises, and this matter of the care of the young affords not the least of them. Nowhere are the links between the present and the past more fascinatingly represented.

I am far indeed from being able to explain many facts I have come to know. I have been puzzled often, and the suggestions I offer I know may be wrong. The early stages in the growth of parental care, even among the animals whose habits are known to us, are often enshrouded in mystery, baffling the penetration of the most patient and careful inquirers. Nevertheless, during recent years a host of facts have been gathered together which throw much new light not only on the theme of pre-human parenthood, but also on the probable action of the parental instinct as it has slowly developed through the ages.

But apart from such more speculative considerations there are yet other aspects to be considered, such as the effect of the environment, the conditions of the home, and the type of union between the male and the female, all of which have their influence on the duration and kind of care shown by animal parents to their offspring. Some explanation must be sought for the almost bewildering diversity which we find in this relationship; for while the young of some animals (and often among low types where least we should expect it) are jealously guarded and cared for by at least one of the parents, in others there is no trace of such sacrifice and solicitude, and the young are thrown on to the world, orphaned before they are born, and left to live[63] or die as chance decrees. Why is this? Why is the parental instinct so actively strong in some cases, so absent in others? Can we, indeed, hope to find the answer? If we can do this, we shall learn much to surprise and also to instruct us.

In the higher types of animals, with the longer period of infancy, some amount of care for the young is always shown by the mother. All the mammals, without exception, nurse their offspring for a longer or shorter period. Among the birds the young in many species are tended by both parents, and we find many beautiful examples of parental fosterage and protection. But we find also species, like the cuckoos, which thrust the parental duties on to others; and there are others, such as the megapodes, where the mother trusts the incubation of her eggs to natural agencies, and after placing them in a position to get the heat generated by decaying vegetation or that derived from hot springs, leaves them, and exhibits no apparent care for the future welfare of the family.

Here is something to give us food for thought. And the same surprises meet us as we descend the scale of life. The reptiles show little or no parental care, but strangely enough the toads and frogs, and many fishes, furnish us with examples of remarkable forethought, or apparent forethought, for their offspring; and, let it be noted, this solicitude is in most cases shown by the father and not by the mother. Even more remarkable are the insects, among whom, though still lower in the scale, we find the most wonderful cases of parental sacrifice to be met with anywhere in life. Some of these little creatures, indeed, seem to be endowed with a devotion to their young so insistent, that their lives can be described only as a passion of sacrifice.[64] In truth they live but to give life and die. And accompanying this parental sacrifice, first in supplying food for embryonic development, and also, in some cases, affording fosterage and protection during the early stages of growth, we meet the most varied and wonderful behaviour which seems to prove an intelligence that thinks and plans; and, whatever explanation we try to find for these acts of devotion, we still are far from understanding them. Life has its secrets, and we shall probably fail to penetrate these mysteries. All that is possible to us is to inquire humbly that we may learn a few truths.

But for the sake of clearness, let me cease from generalising and direct our attention to certain definite examples. I will select first the model household of the Minotaurus Typh?us in the order Coleoptera—

“The female digs a large burrow which is often more than a yard and a half deep and which consists of spiral staircases, landings, passages and numerous chambers. The male loads the earth on the three-pronged fork that surmounts his head and carries it to the entrance of the conjugal dwelling. Next he goes into the fields in search of harmless droppings left by the sheep, he takes these down to the first storey of the crypt and, with the aid of his trident begins to reduce them to flour, while the mother, right at the bottom, collects and kneads it into huge cylindrical loaves, which will presently become food for the little ones. For three months, until the provisions are deemed sufficient, the unfortunate husband, without taking any nourishment of any kind, exhausts himself in this gigantic work. At last, his task is accomplished. Feeling his end is at hand, so as not to encumber the house with his wretched remains, he spends his last strength in leaving the burrow, drags himself laboriously along and, lonely and resigned, knowing that he is henceforth good for nothing, goes and dies far away amid the stones.”[10]

Here we have exactly the kind of example we are in[65] search of, and the most important thing to observe is the co-operation of the father with the mother in the work of providing for the family: such male devotion is undoubtedly exceptional.

Some measure of parental solicitude is almost universally common, and even among the lowliest creatures we find convincing proof of this. Among the species of limited resources, where the least care is bestowed and the young are left to look after themselves, the eggs are placed by the mother in a suitable environment so that the young can be sure of a sufficiency of food until they can feed themselves. The numerous caterpillars offer a well-known illustration of this primitive care, where it is common for the eggs to be attached to the food-plant by means of some adhesive covering. More striking is the case of certain weevils, which, in order to endow their young with a suitable home, possess the art of rolling a leaf in which the eggs are laid, thus forming a nursery, which serves as board and lodging in one.

Fabre, in a wonderful account of the most skilful of these workers, the Poplar weevil, states that not far from the scroll, made and laboriously rolled by the mother, we almost always find the male. But do not make a mistake. The weevil father is not moved by devotion to the family interests as was the father in the last case we examined. No, rather he is filled with the egoistic desire of the male. But I must give the history as Fabre relates it, fearing to spoil his beautiful account by my own halting description—

“What is he doing there, the idler? Is he watching the work as a mere inquisitive onlooker? From time to time I see him take his stand behind the manufacturer, in the groove of the fold, hang on to a cylinder and join for a little in the work. This is a means of declaring[66] his flame and urging his merits. After several refusals and notwithstanding advances made by a brief collaboration at the scroll, the impatient one is accepted. For ten minutes the rolling is suspended. The male still looks on. Sooner or later a new visit is paid to the worker by the dawdler, who, under pretence of assisting, plants his claws for a moment into the rolling piece, plucks up courage and renews his exploits with the same vigour as though nothing had yet happened. And this is repeated four or five times during the making of a single cigar.”

Here, it may be remarked in passing, we seem to see the first faint expression of the father’s interest in the family, which, if I may hazard a guess, may have started in this way as a means of gaining his desire with the female. The correctness of this surmise will receive considerable confirmation as we proceed with our inquiry. And if analogies with animal conduct were not so apt to be misleading, I would venture to suggest the persistence of the same egoistic factor among many human fathers. But for the present I must leave this question.

From the very beginning of life parental sacrifice is more common in the mother; it is in exceptional cases that her devotion is shared by the father. But such good fathers are of special importance to our inquiry. Even more interesting are those species among which the father takes all charge of the young, while the mother spends her time away from the family. Nor is this departure from what we may call the normal order of the family so surprising as at first sight it may seem, if we can account for the necessity under which probably it arose and seek to explain it.

The welfare of the young is a matter of vital urgency; instinct dictates to the animals what reason dictates to us. Nature, as if to show her resourcefulness, her love of[67] successful experiments, is always discovering contrary ways of attaining the same end. And what I wish to make clear is this: when, for some reason that we do not know, the family cares are neglected by the mothers, the work of tending and feeding the young is undertaken by the fathers. I shall have much more to say on this question at a later stage, and I ask you to keep it persistently in the focus of your attention. I desire to emphasise it at once. Whatever groups of animals we survey, we shall find examples of this replacement of the mother by the father, new aspects of the family, which may afford us a better grip of some problems that at present elude us.

The reality of the mother’s regard for the young is proved among many insects by the building of a nest to safeguard the family. The Anthidium, or tailor-bee, and the Chalicodoma, a species of wild bee, afford illustrations of this maternal forethought. In the former case the eggs, when laid, are placed in the ground, protected in cotton-felt satchels made by the mother from fibre which she scratches with her mandibles from the cobwebby stalks of the yellow centaury; the Chalicodoma works with cement and gravel carefully selected from some ruined building, and with such difficult material she fashions her nursery. Even more remarkable is the home of the Magachilles, or leaf-cutting bee. The mother bee, using her mandibles as scissors, cuts pieces from the leaves of the trees, wherewith she forms thimble-shaped wallets to contain the honey and eggs; the larger oval pieces which she cuts make the sides and the floor, and the round pieces the lid or door. These leaf-formed thimbles are placed in a row, one on top of the other, sometimes as many as a dozen being used. The cylinder thus formed is fitted into the[68] deserted home of some other insect, such as the tunnels of fat earth-worms, the apartments bored in the trunks of trees by the larv? of the Capricorn beetles, or, failing these, a reed stump or crevice in the wall is selected. But the choice of the home is always carefully made, it would seem, according to the tastes of the mothers. This structure, in part made and in part borrowed, forms the leaf-cutter’s nest.[11]

Numerous cases of home-making might be recorded, and the difficulty rests in the selection. Many spiders and the book scorpion carry their eggs in a silken bag attached to the under surface of the body. There is a case recorded that shows heroic devotion on the part of one spider mother. She was placed (in order that her behaviour might be watched) in the pit of an ant-lion. At once the enemy seized the eggs and tore them from her charge. Then the mother, though she was driven out of the pit, returned and chose to be dragged in and buried alive rather than desert her charge.[12]

A regular process of incubation is practised by the mother earwig, and the young, when hatched, keep close to her for protection. Special food for the young is prepared by many mothers, as, for instance, among the apid?, who prepare a disgorged food in the form of a sweet milk juice. The Hymenoptera mothers, upon whom the cares of motherhood devolve in their fulness, provide board and lodging for their family. Stores of insects are caught and preserved in the nursery larder, being cunningly paralysed so that live food may be ready when[69] needed by the children. These clever mothers, as Fabre has shown us, become masters of a host of arts for the benefit of a family which their faceted eyes will never see.

Of the domestic economy of the bees and ants whole volumes might be, and have been, written. The habits of the termites, the so-called white ants, are less widely known, although they show one of the most remarkable developments of the family that I have met. Each colony is really a patriarchal family, in which the members, all the descendants of a single pair, live in a community, and work in different ways. All the individuals are at first true males and females. Some of these develop slowly, but grow up perfect insects able to form new families. But the workers and the soldiers have to pass a period of youthful servitude in the community. These develop quickly, and grow up blind and wingless, and their reproductive organs remain in a condition of arrested development. Some of these are workers, and carry out the duties of the community; others at the same time develop jaws and heads of enormous size. It is their duty to defend the colony. And from this has come about the strange condition of their being so altered and trained for their special work that they cannot pass on to the normal life and normal duties of perfect individuals.

Among the bees and some social wasps there is a further step, and only females are selected to do household work, and modified so that they lose the ordinary personal instincts and devote themselves entirely to working for the community, while the males develop only the instincts and capacities of sex. In some species of wasps, however, the males do some work, chiefly domestic, for which they are fed by their foraging sisters. In the communities of ants,[70] as in the termites, there are individuals modified to serve as workers and as soldiers; but here again they are all arrested females, and the males are used only for the purpose of sex. The colonies of ants last much longer than those of the bees and wasps, which are annual, and this has given the possibility of the elaboration of a very complex and extraordinary community.[13]

We are always being surprised by new experiments in family life which show the ready adaptation of habits to special circumstances. A bald statement of these facts seems to tell very little. I leave untouched a whole series of devices and wonderful behaviour—so much that I should like to record. In all these cases we see the maternal instinct in the making. But so varied and so fitting to the needed purpose are the actions of these lowly parents that much which they do gives an impression of the inexplicable—even the magical.

It is common to explain everything by the word “instinct.” But does this explanation take us very far? An elaborate instinctive capacity is probably the result of adding on one contrivance after another to a simpler common habit. And this is surely the same as saying that these little creatures have the power of learning through experience. A beginning of the instinct of caring for the young is exhibited when the mother insect chooses a favourable food position wherein to lay the eggs. Nor is it difficult to imagine how this maternal forethought may have grown out of an earlier habit, for it is but a step, though a great one, from collecting food for self—an instinct that may be traced back and back—to the habit of[71] providing and collecting food for others. Then, this instinct of caring for the future being strongly fixed, it, in some cases and under certain favourable conditions, leads on and on to the specialised maternity and climax of parental sacrifice and devotion, such as may be illustrated by the admirable scarabees, or dung-beetles, of the Mediterranean region and elsewhere.

I have given one case of perfect parents, the Minotaurus Typh?us; but I wish to review such conduct more fully. The family qualities of the dung-beetles are so devoted and so striking, they will repay our study.

The late M. Fabre describes in his inimitable way the nursery which makes the centre and life of the scarabees’ home. These dung-workers edify us with their morals. Both sexes co-operate in making the burrows which serve as a larder for food and a nursery for the young. They are cavities dug in soft earth, usually in sand, shallow in form, about the size of one’s fist, and communicating with the outside by a short channel just large enough for the passage of the balls of dung-food. Both parents work with equal zeal to found a household. “The father is the purveyor of victuals and the person entrusted with the carrying away of rubbish. Alone, at different hours of the day he flings out of doors the earth thrown up by the mother’s excavations; alone he explores the vicinity of the home at night in quest of the pellets whereof his sons’ loaves shall be kneaded.

“A most careful choice of material is undertaken, and often the devoted husband and father is compelled to search long and far for pellets freshly dropped, for whereas coarse bread crammed with bits of hay is good enough for his own and his wife’s food, he is always more[72] careful where the children are concerned. Legful by legful, with slow and most patient labour, the material is heaped up and rolled into a ball. Then the food-ball has to be carried to the burrow; no easy task. Even then the father’s labours are not ended; on reaching the burrow, it is his work to shred the dung-food into flour, which he pours down to the mother for her to knead into the children’s bread. Finally, when the last task is accomplished, the dung-father goes out alone to die. He has gallantly performed his duty as a paterfamilias; he has spent himself without stint to secure the prosperity of his kith and kin.”

The devotion of the dung-father is equalled by that of the dung-mother. More skilled than her spouse in domestic matters, she is occupied always in the home, where she works in the lower floor of the burrow, which she has prepared for the nursery. Here she kneads and forms the cylindrical loaves in which the eggs are placed. In some cases she does more, and we find several species of the dung-mothers anticipating the suckling of the young, the supreme expression of maternal solicitude. These mothers chew the dung-food, and out of it prepare a frothy pap or cream, with which they cover the walls of the nest to form a special first meal for the emerging grub. Throughout her working life the dung-mother never leaves the home. It should be noted that her family is always a very small one: does this, perhaps, explain the parental devotion? From the first fortnight in May, when the eggs are laid, the mother mounts guard over her children. Never does she eat herself, as she will not touch the food prepared and needed for them. She watches through the long months until the coming of the autumn rains in September. Then,[73] when the day of release comes at last, she returns to the surface, accompanied by her family. At once her children leave her; unmindful of her devotion, they go off to find food and begin life for themselves. Thereupon, having nothing left to do, she dies, and ends her sacrifice.

Before I leave this fascinating record of the dung-beetle parents, space must be found wherein to note further certain of their characteristics and habits, which are of special interest to my inquiry as they would appear to be directly connected with the highly developed family qualities of these insects. Fabre tells us that there is no outward difference between the two sexes among the dung-beetles. I call attention to this fact, which I am not able to explain. The scarabees are among the most beautiful of all insects, and the female and male share the same glory. It is my belief that the secondary sexual characters are directly dependent on the occupational activities of the species, as also on the form of union or marriage which pertains and the strength of the parental emotions. Thus, when the male and the female are equally devoted to each other and to the family and its care, many cases among these pre-human parents seem to prove that such devotion and occupational union tends to lessen the ornamental sexual differences in the secondary physical characters. This is a question of profound interest, and demands more attention than it has yet received.

The second fact is of even greater importance to us. The form of union or marriage common among the dung-beetles[74] would appear to be an unusually strict monogamy. These insects, as we have seen, associate in couples, and there is strong evidence that the male remains faithful to his spouse. Such admirable conduct is the more remarkable when we remember that the mother is held in the nursery by her duties during the greater period of the marriage; and meantime the father has to wander far in search of food, making frequent excursions outside the home, but he resists the temptations to which these outings are likely to lead, and always he returns to the home, where he wears himself out for his family.

To test the strength of this conjugal fidelity Fabre made an experiment with the dung-beetles of whose habits I have before spoken, the Minotaurus Typh?us. He placed two couples of these beetles in an enclosed space, marking one of the couples. He allowed them to begin the making of their burrows or homes, then he separated the couples and destroyed the half-made burrows. Once, twice, and a third time he did this, causing confusion among these peaceful workers. But on each occasion the couples came together in the same order; the right male and female knew each other, and, taking little notice of the tumult, each time again they began their work of home-making.

Five more times Fabre separated them and broke up their homes. The result I will give in Fabre’s own beautiful words—

“Things are now spoilt, sometimes each of the four that are experimented on settles apart, sometimes the same burrow contains the two males or the two females, sometimes the same crypt the two sexes, but differently associated from what they were at first. I have abused my powers of repetition. Henceforth disorder reigns. My daily shufflings have demoralised the burrowers, a crumbling home always requiring to be begun afresh has put an end to lawful[75] associations. Respectable married life becomes impossible from the moment when the house falls in from day to day.”

I have now said enough, I think, to show that at many different levels in the insect kingdom the parental instinct is already developed. Pre-eminent in virtue is the behaviour of the dung-beetle parents. And this is all the more interesting as it proves how closely related good parenthood is with the conditions of the home and the form of marriage.

A few more words may here be added to what has been said already concerning the influence of intelligence on instinct. It is a difficult question, but, speaking roughly, intelligence may be said to act in two opposite ways; that is, it may aid both in the making and the unmaking of instincts.[15] Thus the dung-beetles frequently change their conduct, and they do this by modifying their instincts through intelligent adaptation. It is scarcely too much to say that with them intelligence reaches its highest form of originality. Why is this? Fabre gives us the answer. “The more the maternal instinct asserts itself, the higher does instinct ascend.”

It would be better probably if the word instinct were used in a more restricted sense: it should not be regarded as being able to explain everything. This mysterious impulse is held to direct all pre-human parents in their conduct to their young. Very well; but what of the directing force behind? The evidence is strong that even the lowliest creatures have their own problems, and are able to solve them. Can we explain otherwise the wide difference[76] in conduct between parent and parent? Do we know what it is that gives a special direction to the instinctive activities in the accomplishment of a design greater than any of these parents know? We cannot answer fully. But instinct has its twin brother in intelligence, and, acting together, they are the guardians of life.

When real things are so wonderful, what can we do but note them and try to understand? Not elsewhere in the insect world do we meet with a devotion more complete than that of both the dung-parents; not elsewhere do we find a finer development of intelligence. These two things are related and closely dependent, the one upon the other. It is this fact that now I am seeking to establish. Sacrifice in the parent does not lead to limitation, but to expansion.

At this early stage of life the care of the young is as a rule very slight, and often is confined, as I have shown, to the laying of the eggs in a favourable position, where the grub can find food. “The higher inspirations of the intellect are banished among these insects.” I quote again from Fabre, whose opinion on this question so strongly confirms all that I wish to make clear. He asserts further: “The mother neglects the gentle cares of the cradle, and the prerogatives of the intellect, the best of all, diminish and disappear, so true is it that for animals, even as for ourselves, the family is the source of perfection.” And again: “Placed in charge of the duration of the species, which is of more serious interest than the preservation of individuals, maternity awakens a marvellous foresight in the drowsiest intelligence.… The more maternity asserts itself, the higher does instinct ascend.”

We cannot get away from this; it is one of the unalterable laws of life.