Animal Intelligence / The International Scientific Series, Vol. XLIV.

by George John Romanes

Impure air within the hive is that which the bees must above all things fear and avoid, for with the pressure together of so many individuals in a comparatively small space, it would not only be directly harmful to individual bees, but would produce among them dangerous diseases. They therefore also never void their excrements within, but always outside the hive. While this is very easy to do in summer, it is, on the contrary, very difficult in the winter, when the bees sit close together and generally motionless in the upper part of the hive, and when, from impure air and foul evaporations, as well as from bad and insufficient food, dysentery-like diseases break out among them, and often carry off the whole community in a brief space of time. In such cases they utilise the first fine day to relieve themselves, and in the spring they take a long general cleansing flight. But they also know how to take advantage of special circumstances so as to perform the process of purification in the way least harmful to the hive. Herr Heinrich Lehr, of Darmstadt, a bee-keeping friend of the author, has sent the following communication:—During an epidemic of dysentery in winter, from which most of his hives suffered (as the bees were no longer able to retain their excrements), one hive suffered less than the others. Exact investigation showed that this hive was soiled all over at the back with the excrement of the bees, and that the inmates had here made a kind of drain. On this spot a little opening had been made by the falling off of the covering clay, which led directly to the upper part of the hive, where the bees were accustomed to sit together during the winter. This excellent opportunity, whereby they could reach in the shortest way an otherwise difficult object, and one rendered complicated by circumstances, did not escape them.

It sometimes happens that mice, slugs, &c., enter a beehive. They are then killed and covered with a coating of propolis. Réaumur says[70] that he once saw a snail enter a hive in this way. The hard shell was an effective protection against the stings of the bees, so the insects smeared round the edges of the shell with wax and resin, fastening down the animal to the wall of the hive, so that it died of starvation or want of air. If the encasing of an animal (such as a mouse) with propolis is not sufficient to prevent its putrefaction, the bees gnaw away all the putrescible parts of the carcass and carry them out of the hive, leaving only the skeleton behind. The dead bodies of their companions are also carried out of the hive and deposited at a distance. There is no question about this fact (which it will be remembered is analogous to that already mentioned in the case of ants); according to Büchner, however, bees not only remove their dead, but also, occasionally at least, bury them. But as he gives very inadequate evidence in support of this assertion, we may safely set it aside as insufficiently proven.

Büchner, however, gives an admirable summary, and makes some judicious remarks on the well-known and highly remarkable habit which bees practise for the obvious purpose of ventilating their hives. As this account gives all the facts in a brief compass, I cannot do better than quote it:—

Very interesting, and closely connected with this characteristic of cleanliness, is the conduct of the so-called ventilating-bees, which have to take care that in summer or hot weather the air necessary for respiration of the bees in the interior of the hive is renewed, and the too high temperature cooled down. The latter precaution is necessary, not only on account of the bees working within the hive, to whom, as already said, a temperature risen beyond a certain point would be intolerable, but also to guard against the melting or softening of the wax. The bees charged with the care of the ventilation divide themselves into rows and stages in regular order through all parts of the hive, and by swift fanning of their wings send little currents of air in such fashion that a powerful stream or change of air passes through all parts of the hive. Other bees stand at the mouth of the hive, which fan in the same way and considerably accelerate the wind from within. The current of air thus caused is so strong that little bits of paper hung in front of the mouth are rapidly moved, and that, according to F. Huber, a lighted match is extinguished. The wind can be distinctly felt if the hand be held in front.

The motion of the wings of the ventilating bees is so rapid that it is scarcely perceptible, and Huber saw some bees working their wings in this way for five-and-twenty minutes. When they are tired they are relieved by others. According to Jesse, the bees in very hot weather, in spite of all their efforts, are unable to sufficiently lower the temperature, and prevent the melting of some of the wax; they then get into a condition of great excitement, and it is dangerous to approach them. In such a case they also try to mend matters by a number leaving the hive and settling in large masses on its surface, so as to protect it as much as possible from the scorching rays of the sun.

Although the described plan of ventilation is remarkable enough in itself, it is yet more remarkable in that it is clearly only the result of bee-keeping, and is evoked by this misfortune. For there could be no need of such ventilation for bees in a state of nature, whose dwellings in hollow trees and clefts of rocks leave nothing to be desired as to roominess and airiness, while in the narrow artificial hive this need at once comes out strongly. In fact, the fanning of the bees almost entirely ceased when Huber brought them into large hives five feet high, in which there was plenty of air. It follows, therefore, that the fanning and ventilating can have absolutely nothing to do with an inborn tendency or instinct, but have been gradually evoked by necessity, thought, and experience.

As the following observation on the cautious sagacity of wasps is, so far as I am aware, new, and as it certainly does not admit of mal-observation, I introduce it on the authority of a correspondent, the Rev. Mr. J. W. Mossman, who writes from Tarrington Rectory, Wragby. He found an apple in his orchard which had fallen from a tree in apparently good condition; but on taking it up observed that it was little more than a shell filled with wasps. Giving the apple a shake, he saw a wasp slowly emerging from a single small aperture in the rind:—

This aperture was sufficient, and only just sufficient, to admit of the ingress or egress of a single wasp. The circumstance which struck me as very remarkable was this—that the wasp did not make its way through the aperture with its head first, as I should have expected, but with its tail, darting out its sting to its utmost extent, and brandishing it furiously. In this manner it came out of the apple backwards. Then, finding itself in the open air upon the outer surface of the apple, it turned round, and without any attempt to molest me, flew off in the usual way. The moment this first wasp had emerged, the sting and tail of another was seen protruding. This, too, I watched with much interest, and exactly the same process was repeated as in the case of the first. I held the apple in my hand until some ten or a dozen wasps had made their exit in the same identical manner in each individual case. I then threw down the apple, inside of which, however, there were still apparently a good many wasps.

It seemed to me at the time, and I have always felt since, that the wasps coming out of the apple backwards, brandishing their stings as a defensive weapon against possible enemies, whom of course they were not able to see, was an evidence of what would be called thought and reflection in the case of human beings. It seems to me that these wasps must have reflected that if they came out of the narrow aperture in the apple, which was their only possible means of ready egress, in the usual manner, head first, they might be taken at a disadvantage by a possible enemy, and destroyed in detail. They, therefore, with great prudence and foresight, came out of the apple backwards, protecting themselves by means of their chief offensive and defensive weapons, their stings, which, according to their normal method of locomotion, would have been useless to them as long as they were making their exit.

With regard to the tactics displayed by hunting wasps I may quote the following cases:—