Fanning
Scent-Fanning by bees is a form of communication. When a bee stands in the position of the bee in the picture and fans air over the scent coming out of the scent gland, the scent evaporates (becomes a gas) and spreads a long distance in the stream of air to the rear of the bee, Other worker bees that smell the odor are attracted by it and fly to join the farming bee. The odor is in fact a chemical message of very general meaning which in human terms could be translated as ”Come here... this is the right place to be”.
There are several situations in which bees use scent-fanning. In all of these the odor appears, to help other bees find the fanning bee. The bees “leading" a swarm of bees to a new nest scent-fans at the entrance of the new nest. Most of the bees can then find the entrance and land there. Also, when a flying swarm of bees is on the way to a new nest the queen may sometimes get separated from the others. The queen has her own odor which helps the workers to find her. If the queen is separated, the first bees that find the queen stop and scent-fan. Sometimes food gathering bees scent-fan when they find a very rich food supply, such as a plant that makes very large amounts of nectar or pollen. This apparently helps other food helps gatherers to find the plant.
Bees do not learn how or when to scent-fan. They just seem to be able to respond in this way when conditions are right. It is the same for other activities. Bees do not learn to build comb —they can do it without ever having seen comb before. They do not learn how to collect pollen - although they do improve with practice.
Most fanning that is done inside the hive, or nest, is done to control temperature, humidity and perhaps the concentration of carbon dioxide gas. This gas, which is produced naturally by living things, could suffocate the bees if there were too much of it. During the spring and summer, bees fan fresh air into the hive at one place and out again at another. If a feather is held near the hive entrance it is drawn in. If it is held near another opening it is blown away. This shows the pattern of air currents. If bad odors or smoke happen to be drawn in, the bees reverse the air currents so that the area where the air usually goes in becomes the vent area, and the smoke is driven out.
By controlling air flow in the nest bees can also control the temperature. If the temperature in the nest went much above its normal temperature of about 94°F, all the developing larvae would die and the wax of the comb would melt. So, in desert areas where the temperature may go as high as 115°F some of the food collecting bees collect drops of water as soon as the temperature in the nest starts to rise. Other bees place the drops of water all over the inside of the nest. Still other bees fan the air causing the water to evaporate, until the temperature in the hive drops to the normal 94°F. By controlling the speed of air flowing through the hive, the rate at which the water evaporates is controlled. In this way the bees can control the hive temperature exactly. Man certainly was not the first to use air conditioning.
Fanning also helps to evaporate water from nectar. The nectar is spread thinly over the mouth parts of some workers and in the storage cells. Constant fanning reduces the nectar to a very thick mixture of sugars and water that we call honey.
As bees grow older the tips of their wings become so worn and ragged from flying and fanning that they can no longer fly.
The Bees section was created with special thanks to Louis Juers (Arizona State Parks & Trails) for providing information used in this section. Additional information and digital materials were obtained from some of the following organizations. We would like to thank them for all their dedication and hard work within their profession.
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