students of the ways of the honey-bee find many things to marvel at, but little to excite their wonder more than the unique system of ventilation established in the hive.
under natural conditions it is a moot point whether bees concern themselves at all with the ventilation of their nests. wild bees usually fix upon a site for their dwelling where there is ample space for all possible developments; and the ventilation of the home—as with most human tenements—is left pretty much to chance causes. at least, in the course of many years’ observation, the writer has never seen the fanners at work in the entrance of a natural bee-settlement.
probably this remarkable fanning system originated in a new want felt by the bees, when, in remote ages, their domestication began, and they found themselves cooped up in impervious hives which, in their very earliest form, were possibly roughly-plaited baskets, daubed over with clay, or earthen pots baked dry in the sun. this form, originally adopted by the bee-keeper as a protection against honey-thieves of all sorts, as well as against the weather, brought about a new order of things in bee-life. the free circulation of air which would obtain when the bee-colony was established naturally in a cleft of a rock or in a hollow tree became no longer possible. and so—as they have been proved to have done in many modern instances—the bees set to work to evolve new methods to meet new necessities, and the present ventilation-system gradually became an established habit of the race.
watching a hive of bees on any hot summer’s day, one very curious, not to say startling, fact must strike the most superficial observer. if the fanning bees were stationed round the flight-hole in a merely casual, irregular way, their obvious employment would be surprising enough. but it is at once seen that each fanner forms part in an ingenious and carefully thought-out plan. outwardly, the fanners are arranged in regular rows, one behind the other, all with their heads pointed towards the hive, and all working their wings so fast that their incessant movement becomes nearly invisible. these rows of bees extend sometimes for several inches over the alighting-board, and on very hot days there may be as many as seven or eight ranks. the ventilating army never covers the whole available space. it is always at one side or the other; or, where the entrance is a wide one, it may be divided into two wings, leaving a centre space free. the fanning bees, moreover, do not keep close together, but stand in open order, so that the continual coming and going of the nectar-gatherers is in no wise impeded. there is a constant flow of worker-bees through the ranks in both directions; yet the fanning goes on uninterruptedly, and, under certain conditions, the current of air thus set up may be strong enough to blow out the flame of a candle held at the edge of the flight-board.
in all study of the ways of the honey-bee, the safer plan is to begin with the assumption that a reasoning creature is under observation, and then to work back to the surer, well-beaten tracks of thought concerning the lower creation—that is, if the observed facts warrant it. but this question of the ventilation of the modern beehive—only one of many other problems equally astounding—helps the orthodox naturalist of the old school very little on his comfortable way. we know that the wild bee generally chooses a situation for her nest which is neither cramped nor confined, but has in most cases ample space available for the future growth of the colony. security from storm or flood seems to be the first consideration. the fact that the interior of a bee-nest is more or less in darkness appears to be mainly accidental. bees have no particular liking for absolute darkness, nor, in fact, is any hive perfectly free from light. experiment will prove that a very small aperture is sufficient to admit a considerable amount of reflected and diffused light, quite enough for the needs of the hive. it may be supposed, therefore, that the bees would have no objection to building in broad daylight, or even sunlight, if, in conjunction with the first necessities of shelter, security, and equable temperature, such a location were easily obtainable under natural conditions. it would only be another instance of their unique adaptability to circumstances forced upon them.
in the matter of ventilation, however, they seem to make a very determined and highly successful stand against imposed conditions. bee-keeping cannot be made a profitable occupation unless the work of the bees is kept strictly within certain sharply-defined limits, and probably the modern movable comb hive is the best means to this end. that it leaves the necessity of ventilation wholly unprovided for is not the fault of the bee-master, but of the bees themselves. they refuse pointblank to have anything to do with human notions of hygiene. many devices have been tried, in the form of vent-shafts and the like, to carry off the vitiated air of the hive, but all have failed, because the bees insist on stopping up every crack or crevice left in walls, roof, or floor. for some inscrutable reason they will have only the one opening, which must serve for all purposes, and the hive-maker has had to learn by hard-won experience that the bees are right.
perhaps, in any attempt to follow the reasoning of the bees in this matter, it is well first of all to get rid of the word “fanning” altogether. the wing-action of the ventilating bees is more that of a screw-propeller than a fan. the air is not beaten to and fro, as a fan would beat it, but is driven backwards, and thus the ventilating squadron on the flight-board really sets up an exhaust-current, which draws the contaminated air out of the hive. this implies an equally strong current of fresh air passing into the hive, and explains why the bees work at the side of the entrance only, the central, unoccupied space being obviously the course of the intake. thus the bees’ system of ventilation can be described as a swiftly-flowing loop of air, having both extremities outside the hive, much as a rope moves over a pulley, and it can be readily understood that any supplementary inlet or outlet—such as the bee-master would instal, if he were permitted—would be rather a hindrance to the system than a help. probably the actual main current keeps to the walls of the hive throughout, the ventilation between the brood-combs being more slowly effected. this would fulfil a double purpose. the air supplied to the central portion, or brood-nest proper, would be thoroughly warmed before it reached the young larva, while the outer and upper combs, where the stores of new honey are maturing, would lie in the full stream.
it must be remembered that a constant supply of fresh air of the right temperature is as necessary for the brewing honey as it is for the bees and young brood. the nectar, as gathered from the flowers, needs to be deprived of the greater part of its moisture before it becomes honey. thus, in the course of the season, many gallons of water must pass out of the hive in the form of vapour, and the removal of this water constitutes an important part of the work of the ventilating army. here, again, the wisdom of the bees in insisting on a mechanical, as opposed to an automatic, system of air-renewal, becomes evident. if the warm, moisture-laden air were left to discharge itself from the hive by its own buoyancy, condensation of this moisture would take place on the cooler surfaces of the hive-walls, and the lower regions of the hive would speedily become a quagmire. but by setting up a mechanically-driven current the air is drawn out before condensation can take place, and thus, in one operation, forming a veritable triumph in economics, the hive interior is rendered both dry and salutary, while its temperature is sustained at the necessary hatching-point for the young brood.
a reflection which will occur to most thinking minds is, why should the domesticated honey-bee be constrained to resort to all these devices, when the wild bee seems to lead a happy-go-lucky existence, comparatively free, so far as we know, from such complicated cares? the answer to this is that the science of apiculture has wrought a change in the bees’ normal environment which is probably without parallel in the whole history of the domestication of the lower creatures. in a modern hive the honey-bee lives on a vastly elaborated scale, and the ancient rules of bee-life are no longer applicable. much the same sort of thing has happened as in the case of a village which has grown to a city. it is useless to deal with the new order of things as a mere question of arithmetic. abnormal growth in a community involves change not only in scale but in principle; and it is the same with a hive of bees as with a hive of men.
