A soldier, too, has been observed to kill and partially eat one of its worker companions, nor is it altogether uncommon for an individual of any class, after licking, for some little while, the leg of another, suddenly to snap it off. The bond of union, therefore, though sufficiently developed to allow of an elaborate social organisation, is not so strong between members of the same termitary as it is in the case of ants, amongst which latter such unseemly conduct is never known to occur. So, too, unless a particular chemical substance, which seems to have a maddening effect, be flung amongst them, ants of one community never attack each other. Amongst white ants, however, warfare will occasionally break out within the nest, more especially if this be disturbed, in which case the soldiers are apt to turn savagely on those nearest to them, perhaps considering them as the cause of the calamity. Still, upon the whole, order, and, if not friendship, at least co-operation, is conspicuously displayed, and the majority often interfere to put a stop to such individual or partial combats as may from time to time break out.
There is more excuse for the soldier termites in their cannibalistic propensities, since owing to the special development of their jaws, which are long and slender, they are unable to triturate wood, which is the basis of diet of these insects. They might die, therefore, but for such occasional lapses, were it not the common practice for all members of the community to feed one another, though the soldiers, for the above reason, are much more dependent on such aid. The food thus administered has just been swallowed by the individual who parts with it. Such transfer is performed in two ways, the first of which is familiar enough—that process, namely, known as regurgitation—but the second and more staple one is too peculiar to be dealt with in a non-scientific work. When a termite regurgitates, an exceedingly small round pellet of reddish-brown colour may be seen, by attentive observation, to form about the mouth, and gradually to increase in size till it becomes plainly apparent, and is seen to consist of food—that is to say, wood—which has previously been swallowed, in a moistened and softened condition. Sometimes this pellet is used for building purposes, but often another termite comes forward, receives, and swallows it.
Another article of diet which has a peculiar efficacy, and is used for a certain purpose, has been already alluded to—viz. saliva. This, we are told, “issues,” when required to do so, “as a colourless and distinctly alkaline liquid. It collects on the labium (the insect equivalent of lips) as a small drop, which may be employed either as a cement in building or as food for others. These may either possess themselves of the drop and then retreat a little way in order to swallow it gradually, or they may receive it from the one which secretes it and clearly provides it for them as an article of diet. The assimilation of a drop requires a certain number of acts of deglutition, which may be counted, and are usually four or five.”[[9]] Very young larvæ (the whole community, it must be remembered, are either in this or the pupal state) are fed after this fashion, until sufficiently advanced to be able to swallow wood-meal. Under this course of diet the abdomen becomes remarkably transparent, and this, in older individuals, is an indication that they are being bred up by the workers to become royal substitutes. The development, therefore, of termites from the larval to the perfect, or, at least, the sexually perfect form, seems to be wholly dependent on their being fed with this substance.
As is well known, the body of the queen termite, in the African and other tropical species, swells, when about to lay, to an enormous size, but this is not nearly so noticeably the case with her European representatives. Neither is a cell, in this case, constructed for her accommodation, but the royal pair, whether they are true king and queen, or only substitutes, “remain, in close proximity, in the heart of the nest, where the inmates are always most crowded.” They are not imprisoned, therefore; but can go from one place to another, should they, as sometimes happens, wish to change their situation. In this they would seem to be happier than their more specially accommodated royal cousins, but no doubt, with the latter, or at any rate with the queen, the instinct of locomotion ceases with the capacity to indulge in it. The purpose of the specially made cell is probably rather to guard than to restrain the queen.
In regard to the swarming of white ants—another habit in which we are reminded both of ants and bees—with the subsequent founding of a new colony, Professor Grassi has the following remarks to make. They apply more especially to the larger of the two European species, viz. Calotermes. “Before swarming,” he tells us, “they collect near one of the exit-holes of the termitary, and when the proper time comes, issue from it in ones or twos, so that the twenty or thirty members who are ready to take flight emerge in perhaps a quarter of an hour. Once outside, they run upwards, if the locality admits of it, for a few metres, and then only do they take wing. In a room they fly towards the light, and if a wind is blowing they follow its direction. Some, becoming tired, settle soon upon trunks of trees, and all may do this eventually. Here they group themselves into pairs, the males and females of which must frequently be derived from separate nests, since the sexes swarm separately; this acts as a safeguard by which Calotermes habitually avoids in and in breeding. Matrimonial alliances having been thus formed, the work of excavation commences, each pair seeking for some decayed spot in which to bury themselves and become, in time, the parents of a fresh community. The wings, by this time, have been got rid of. They may be shed by coming into contact with an obstacle, or by getting damp and adhering to some spot, while the insect continues to move. But, if not favoured by chance, the Calotermite purposely rids itself of these now useless encumbrances. Thus four perfect insects were captured after flying about the room, and put under a piece of rotten wood. Hardly had they settled when they stripped off their wings by resting the tips against some projecting corner of the wood, and then moving backwards a little, so that the wings bent near the base, broke, and dropped off. When rid of them they began to gnaw the wood, at first along and then across the grain. When they encountered each other by chance they first threatened to bite one another, and then ran off in opposite directions. This was because they were of the same sex. Had they been of opposite ones, an attachment, under such circumstances, would no doubt have been formed between them.”[[9]]
This is all the space which I can afford to these interesting insects. There are many other points in connection with them which I might have touched upon, but I thought it better to say less about what may be read by anyone in a score or so of works, and select as my text-book a series of the closest and most interesting observations, which lie buried in the pages of a scientific journal not at all likely to meet the public eye. Where possible, I shall be guided by the same or a similar principle throughout this small work.
CHAPTER III
Ants and white ants—Guest insects—Ants’-nest beetles—Doubtful relations—A strange forbearance—Yellow ants and white wood-lice—Beetles fed by ants.