Honey bees communicate using many different senses. In past blogs ATTTA has highlighted how these eusocial insects use both smell and sight to communicate and function as a colony: “A Honey Bee’s Perspective: Smell” (Thursday August 10, 2023) and “A Honey Bee’s Perspective: Sight” (Thursday June 22, 2023). Another sense used by honey bees to communicate is sound. Bees perceive sound differently than humans, and we will explore throughout this week’s blog what it means for bees to hear.

A Honey Bee’s Perspective: Sound

Past research indicated the bees seemingly could not hear airborne sound¹. However, it was shown that bees can discriminate between something that is silent and something that produces sound, but only if the sound was intense enough to produce vibrations that were felt by the bees. The vibrational sense organ of the honey bee is the subgenual organ, located in the knee of the bee's leg, which allows bees to perceive the queen’s piping sounds. Substrate borne vibrations are generally perceived by different sensory structures than airborne sounds².  Various studies looked for sensory structures of bees that were suitable for detecting airborne sound, but concluded bees do not hear³. This was accepted until the question was revisited by researchers in 1989⁴.

Airborne sound can be either an oscillation of pressure or an oscillation of the molecules in the air⁵. Humans respond to pressure changes, but other animals, such as honey bees, respond to the oscillation of the air molecules⁵. Early investigations on the sense of hearing in honey bees provided stimuli that could only be perceived as sound pressure changes⁵. A study by Towne and Kirchner used a sound signal of high air particle oscillation as the conditioning stimulus for bees, which provided the first direct evidence for a sense of hearing in bees⁴.

In the mentioned study, bees were trained to fly to a feeder, where two different stimuli could be presented: a sound signal and a mild electric shock. The sound signal was similar to the sound made by a dancing bee in frequency and intensity. It was presented for five seconds. Four seconds after the onset of the sound, the electric shock was delivered. The experiment determined that bees could make use of the sound signal in order to withdraw from the feeder before the onset of the electric shock demonstrating bees can hear airborne sounds.

Interestingly, beekeepers have been conducting a particular practice, known as tanging, to induce flying swarms to settle since the 1800s⁶. Tanging is the act of hitting metal objects together to produce a clanging sound and if the practice is truly effective it would indicate honey bees can hear. Although many question the efficacy of tanging, the practice is still used today. However, current research provides no evidence that tanging causes a flying swarm to settle⁶. While honey bees do communicate using sound, they cannot hear in far-field which relies on detecting changes in air pressure⁷. As indicated, honey bees instead hear in near-field which involves detecting the movement of air particles⁷. Given that bees cannot hear in far-field, it is unlikely that bees in a swarm can detect the sound of tanging.

Knowing that bees can hear, Dreller and Kirchner (1995) investigated the frequency range and sensitivity of honey bee’s sense of hearing. Bees can hear sound of low pitch up to 500 Hz. Humans, in contrast, can perceive sound up to 12 000 - 16 000 Hz.

Given that bees' ears are in fact not pressure sensitive like human ears, but particle-velocity sensitive, bees must use structures which can be bent or deflected by air currents, as is true for hairs or antennae⁵. The study by Dreller and Kirchner (1995) concluded that the hearing structures of bees are located on their antennae. The antenna of the honey bee is a complicated structure, which is also used as the bee’s nose. The part of the antenna responsible for the bee’s hearing ability is located in the distal joint of the pedicel of the antenna, known as the Johnston’s organ⁵. The Johnston’s organ is not unique to honey bees, as it exists in nearly all orders of insects⁸.

Drawing of section of honey bee antennae with Johnston’s organ labeled (Erber et al. 2000)⁹.

Honey bees use their sense of hearing to effectively communicate the location of food sources. This is done in addition to their use of dance to communicate forage location. During the straight component of the waggle dance, dancers emit a sound signal^5,10. The sound has a frequency of about 250 Hz^5,9. Dreller and Kirchner (1995) proved that hearing, in addition to dance communication, is necessary for honey bees to perceive information on forage location. The researchers did this by demonstrating honey bees with one removed antennae recruited less bees to learn forage location, and bees receiving the information ended up taking significantly longer to find the food source. Sound perception by the antennae is necessary for successful dance communication and is required to correctly perceive dance sounds⁵. Therefore, bees use and perceive airborne sounds, which provides information about forage location⁵.

There is still more to learn regarding how honey bees utilize their sense of hearing to effectively communicate and function as a colony. To learn more about how honey bees use their senses to operate as a colony, read our blog on October 31st which will explore the honey bee’s sense of taste.

Connecting with ATTTA Specialists

If you’d like to connect with ATTTA specialists or learn more about our program, you can:

visit our website at https://www.perennia.ca/portfolio-items/honey-bees/

Email abyers@perennia.ca

References

1. Hansson, A. 1945. Sound production and sound perception ability of bees. Opus-cula Entomologica suppl 6: 1-124
2. Michelsen, A., Kirchner, W.H., Andersen, B.B. and Lindauer, M., 1986. The tooting and quacking vibration signals of honeybee queens: a quantitative analysis. Journal of Comparative Physiology A, 158, pp.605-611.
3. McIndoo, N.E., 1922. The auditory sense of the honey‐bee. Journal of Comparative Neurology, 34(2), pp.173-199.
   
4. Towne, W.F. and Kirchner, W.H., 1989. Hearing in honey bees: detection of air-particle oscillations. Science, 244(4905), pp.686-688.
5. Dreller, C. and Kirchner, W.H., 1995. The sense of hearing in honey bees. Bee World, 76(1), pp.6-17.
6. Hudson, H. 1871. Arresting absconding swarms. The American Bee Journal. 6(12): 281–282.
7. Smith, M.L., 2013. Tanging does not cause flying swarms to settle. Journal of Apicultural Research, 52(5), pp.190-193.
8. Field, L.H. and Matheson, T., 1998. Chordotonal organs of insects. In Advances in insect physiology (Vol. 27, pp. 1-228). Academic Press.
9. Erber, J., Pribbenow, B., Kisch, J. and Faensen, D., 2000. Operant conditioning of antennal muscle activity in the honey bee (Apis mellifera L.). Journal of Comparative Physiology A, 186, pp.557-565.
10. Kirchner, W.H and Towne, W.F. 1994. The sensory basis of the honeybee's dance language. Scientific American. 27