Bees are very chatty - scientists have identified the source of their sound
Bees in the beehive vibrate their wings at a certain frequency. This may be an element of their communication system, suggest researchers from the University of Agriculture in Krakow, who have been spying on bees with special cameras.
Researchers have been studying the way bees communicate for years. For now, it is known, for example, that these insects transmit information on threats by secreting chemical substances - pheromones. The location of food sources is communicated by means of a dance, in which workers move along the honeycomb in a specific, sequential way.
"We knew that sounds and vibrations could play a role in bee communication. After all there is even a saying +humming like a hive+. We have now managed to prove that the movements of wings of bees sitting on honeycombs contribute to this cacophony" - says Prof. Adam Tofilski from the University of Agriculture in Krakow. He determined that together with Dr Sylwia Łopuch from the same university.
As part of their research, the scientists placed cameras in several hives, recording thousands of frames per second. As a result, they were able to see that bees, including workers, drones and queens that moved on honeycombs inside the hive, moved their wings from time to time in a certain way. The range of this wing movement was small, less than 1 millimetre.
"This movement is not visible to the naked eye. Bees cannot not see it either, because it is completely dark in hives. We believe that the wing movements are accompanied by vibrations that bees feel" - says Prof. Tofilski.
Hearing organs in bees are located inside their legs. That is probably why during the movement of the wings, the bees touch the honeycomb with their bodies, so that the vibrations are transferred more effectively, the scientists explain.
People hear the sounds made by bees in the beehive, but the sounds of a single insect are hard to catch in the general noise. "That is why our finding is so important, now we can focus on observing individual bees and see in what circumstances they move their wings. This way, we may be able to determine what information they are communicating. We will look for patterns in wing movement sequences in different situations" - the scientist says.
Researchers made their discovery using cameras only (without microphones). They focused on the sound source - wings. "If a bee moves its wings about 200 times per second, it must emit sound with a similar frequency" - adds Tofilski. The movement of the wings is certainly not accidental, the researcher says, because bees performing various activities move the wings with different frequencies. Thus, the sound frequencies are also different.
In his opinion, the new finding opens a new path for research on bee communication. "We already have a new finding in the context of the behaviour of drones (male bees). It is a common belief that they do nothing, only copulate with the queen. Based on the analysis of the camera images, we know that they also communicate with other bees in the beehive through the movement of their wings. It is possible that this way they determine the moment of departure from the hive" - the scientist says.
Bees were observed in beehives located at the University of Agriculture in Krakow. Thse are so-called observation beehives, in which honeycombs bees are placed behind the glass. Bees live there just like in other beehives - they can fly out freely. They feed in Krakow.
PAP - Science in Poland, Szymon Zdziebłowski
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