Bees are amazing creatures. Many things about their way of life and structure are unique. The eyes of bees are organised very differently from those of humans. In this article we will look at how bees see. How their eyesight helps them navigate through space and find flowers and their way home.
How bees’ eyes work
If you look at a bee, all you can see are large black eyes located on the sides of an almost triangular head. However, these are not the bee’s only organs of vision. There are three other small eyes, which are located on the forehead in queens and drones and on the parietal in worker bees. The two large eyes on the sides are compound vision, while the three small eyes are responsible for simple vision.
Simple eyes of bees, in number of three pieces are practically the same in all individuals, they are small dots of triangular shape.
Another thing – compound eyes – these are two large lenses on the sides of the head. It is these that many people mistakenly perceive for the only organs of vision of insects. The compound eye of the bee consists of facets – small hexagons, similar to honeycombs. It is believed that their number in different individuals can be from 4 to 10 thousand per eye.
Each type of vision has its own function, and by combining the information into one whole, the insect gets the most complete picture of what is going on around it. This helps worker bees to extract pollen efficiently in meadows, find their way back to their hive, and makes it easier for drones to find a queen during the mating flight.
What is the purpose of simple and compound vision for bees
It is logical that different types of bee vision have different purposes.
The picture produced by three simple eyes does not differ much from each other. It can be compared to photos taken from different angles. They are mainly used to perceive the general illumination.
The two large eyes, located on either side of the head, have a more complex structure. The image obtained from these eyes is fuzzy and blurred – it is used by bees to understand the general environment around them.
To put it simply, bees need large eyes to orientate on the territory, they allow them to see the whole picture, on a large scale. And simple small eyes are needed to determine the level of light.
How a bee sees with its eyes
Bees fly over the terrain at a speed of 20-30 km/h. At this speed their colour vision is switched off – they do not perceive colours. No sooner do the colours appear to the bees than they fly close to the flowers and start circling slowly over them. By the way, bees will not be mistaken: they are quite poor at distinguishing geometric figures, but objects resembling the shape of flowers, insects see more clearly.
For a bee during a fast flight, the colour of objects around is clearly optional information. Bees must concentrate on other concerns that are important during rapid flight, such as recognising the surrounding terrain, where obstacles are located or landmarks that point the way.
The details of the flower the bee is flying towards only become discernible when the bee is very close to it. And small details, pistils – stamens, bees can distinguish when they are a few centimetres away from them. That’s forced myopia.
In general, what is not necessary, the bee sees in general, from many angles, but blurred, and what is necessary – sees clearly.
What colours bees can distinguish
Bees’ vision is tri-coloured. This means that the perception of all colours comes from the mixing of three colours – yellow, blue and ultraviolet. It is only because of the reflection of ultraviolet light that insects see quite differently from humans. For example, violet and blue perceive not as two, but as four different colours. And green and orange as yellow.
In the middle of the twentieth century, German-Austrian biologist Karl Frisch studied the visual perception of bees. Experimentally, he understood that these insects do not perceive the colour red. All because any colour is an electromagnetic wave of a certain length. The wavelength of such a wave in the colour red is above the range that bees can see. It appears black or dark grey to them. This is often used by beekeepers when inspecting hives with a red-coloured torch.
The experiments made it clear to the scientist that insects can distinguish white, yellow and blue colours well.
How bees see in the dark
If the bee has not had time to return to its hive before sunset, dusk is not a problem. It uses the earth’s electromagnetic field, small light sources (starlight, moonlight), and the ability to recognise polarised and ultraviolet light to get its bearings.
In total darkness, the insect is lost in space and is unable to continue moving. Sometimes bees stay overnight in the field when it gets dark, they may huddle together in groups, cuddle and sleep until morning.
Сonclusion
Bees see differently from other animals. But this vision allows them to orientate themselves perfectly in space when flying at high speed. At the same time, it allows them to see and distinguish between different flowers, the source of their nectar and pollen. All in all, evolution has done an excellent job on bee vision. All the essentials and nothing extra.
