Bees have large compound eyes at the sides of their heads and three simple eyes on the top of their heads. The compound eyes consist of thousands of adjacent facets and each of these facets has a small lens at the end. Each simple eye has its own lens. Each facet perceives only a very small part of the field of vision; therefore, the image that the bee sees is formed by adjacent dots whose brightness and colours vary. In other words, the bee has so-called mosaic vision. The more facets the target reaches, the better the bee’s perception. Therefore, the bee sees well only at very close range, it sees fragmented patterns better than uniform ones, as it does a moving object as opposed to a stationary one. From the spectrum wavelengths, a bee can differentiate between yellow, blue-green, blue, violet and ultraviolet. Also, within each wavelength, it can differentiate between shades but it does not see them as well as the major categories of colour. A bee sees red as grey, but red nectar flowers are, after all, purple, so the bee sees them as blue or as reflecting ultraviolet.
A bee does not see the shape of objects but it can use their respective locations when it is navigating. In other words, a bee can differentiate between right, left, front and back as well as above and below.
A bee senses external touch with the sensory hairs that cover its body, in particular its antennae. It uses its sensory hairs to perceive objects, to assess body position, to coordinate movement and to adjust the location of the body in relation to the direction of gravity. Its sense of touch also gives the bee information on bodily functions, for instance, on how full its honey stomach is.
Bees produce various sound signals and they are able to sense them either as base vibration with the sensory organs in their legs or as sound waves with the hairs that they have between their eyes and neck. According to research, bees are able to perceive the length, the strength and the pitch of sounds with their “hearing hairs”. Bees use vibrations and sounds in their communication. For instance, the queen bee can stop the other bees, or the scout bees can cause the swarm to leave.
A bee’s taste organs are located in its tongue, ankles and antennae. It can taste sweet, salty, sour and bitter flavours. Surprisingly, a bee cannot taste sweetness as well as, for instance, a human being can. But this is simply useful to a bee, since gathering only very sugary nectar it avoids carrying excess water to the hive. All of the sugar varieties that the bee perceives as sweet flavours are part of its nourishment. It does not sense or gather artificial sweeteners.
The organs of smell are located in the antennae. The sense of smell is very important to a bee, since it gives the bee information on other bees, for example, on the queen’s condition or on whether a bee that has perched on the hive flight board is from the same hive or a stranger. Also, the foraging bees recognize their own hive with their sense of smell and can find the plant that they are looking for from amongst other similarly-coloured flowers. A bee’s and a human being’s sense of smell is more or less as good, but a bee is more perceptive to the smells that are important to it, for example, the queen’s pheromones.
The regulation of the temperature of the hive, and in particular of the larvae area, is vital for bees. Therefore, bees must have a very accurate sense of temperature. Bees can tell the difference between two places when there is no more than 2oC difference in temperatures. The temperature sensory organs are in the antennae, as are the sensory organs for humidity. A bee can sense the humidity of the air, based on which it knows, for example, that it should stay in the hive when it is raining. It can also “measure” the humidity of the honey so that it knows when to cover the cells at the right time.
It has been noticed that bees behave differently when they are subjected to various electric charges, and this has resulted in the conclusion that they sense the changes in the electric field. The filmy parts of a bee’s skin are good conductors and this is why their electric charge changes easily on the basis of the external charge. A change in the electric charge can change a bee’s behaviour and bees are, in fact, sometimes more aggressive during thunder and when the hive is located close to high-voltage ducts. It is believed that bees take advantage of electric charging in their communication. For instance, when a bee is performing its waggle dance, an alternating-current field is formed. Apparently, bees can also sense the direction of the earth’s magnetic field, since they always build their comb in a particular direction, which they changed during studies in which the magnetic field was artificially changed. The magnetic field also probably has an effect on a bee when it is navigating. A bee senses the magnetic field with the magnetic crystals that it has in the front part of its abdomen.