Along with Earth, Air and Fire, Water is one of the elements common to ancient Greek, Buddhist and Hindu philosophies. And even when modern scientists scan for signs of extra-terrestrial existence, water is the first thing they look for. Water is vital to life. So why don’t bees store water?
After all, bees are rather good at stockpiling life’s other essentials: what is a hive but a custom-built repository for honey and pollen stores? What is a queen bee other than a six-legged silo of eggs and semen?
It’s not as if bees don’t need water. Far from it. It is said that bees need to bring a litre of water a day into the hive during high summer to cool the colony by evaporation, although accurate measurement of the quantity of water coming in is difficult, precisely because it is consumed, not stored. And especially at this wintry time of year, the need to bring in water is highly inconvenient. Yet water is indispensable to dilute granulated winter honey stores for food and also for nurse bees to feed up new brood in early Spring.
Certainly, some moisture from condensation within the hive from the mass of breathing, clustered bees can be recycled in winter. Heater bees vibrate their flight muscles (with wings unhooked), to generate the heat necessary to maintain the temperature of the inner brood chamber at around 35C (compared to human body temperature of 37C). But condensation alone is unlikely to be sufficient once the brood chamber starts to fill up with larvae and young, hive-bound bees.
Impelled by the need to forage for water in the dangerously low temperatures of winter and the first days of Spring, bees risk falling into a “chill coma” at temperatures below 10C. Flying out of the warm hive to a water source in numbing temperatures and then on-boarding half your body weight of stone-cold liquid before taking off on the wintry return to the hive is a risky business. Which makes it even more odd that bees don’t store water.
All the more so, when we consider that mankind has existed on Earth for millions of years less than bees, yet the waypoints of human civilisation have been marked by advances in our water storage capabilities: from stone pools, to gourds, skins, fonts, glass flasks, cisterns, tanks, aqueducts, bath tubs, canals, pipes, hydraulic sumps, reservoirs, sanitation systems and now Evian bottles.
There must be a reason why bees, the animal kingdom’s storage compulsives par excellence, don’t stock up on the one resource which is most precious to them. After all, humanity has tamed water, made it into a domestic amenity. Why don’t bees do the same? For example, the wax from which the bees make their comb could easily be modelled into a rudimentary storage tank for water. What’s the problem ? I’ve hatched two theories: abundance and collateral risk.
Let’s take abundance first. Water is pretty ubiquitous. It covers 70% of the world’s surface, so it is reasonable to assume that bees will be mostly able to choose a hive site close to a reliable and accessible source of potable water. (See my blog post “The Age Of Aquarius”.) They don’t store it, because they’re confident that they will always be able to obtain it.
Collateral risk comes into the equation, since excessive moisture inside the hive can kill bees. In the winter cluster of bees in the hive, respiration and exertion from heat-generation create a modicum of moisture which a well-ventilated hive can deal with. However, if the moisture level rises around the warm core of bees, an evaporation effect chills the bees on the outside of the cluster. Since the cold prohibits the bees from fanning their wings to create a drying current of air, as in summertime, the clammy cold will eventually penetrate to the centre of the cluster. Since too much water in the hive could be fatal, not storing it seems a sensible avoidance of risk.
I’m convinced that the bees would have tested the water storage concept at some stage over the last few tens of millions of years. And the evolutionary outcome has judged decisively against it. Can’t live with, can’t live without it. Perhaps the idea just didn’t hold water.