How Do Bees See?
How do bees perceive the world?
Vision is essential to bees as they must hunt for flowers to find nectar and pollen. Because
of this, they are well adapted to be able to seek the right plants. Bees can use odor cues to
hone in on a flower, but that only works when they’re already pretty close. Vision is essential
to help the bees find flowers at a distance.
It is often said that a bee has 5 eyes, 3 ocelli eyes and 2 compound eyes, but that is somewhat
misleading,
The 3 ocelli or 'simple eyes' poke up like glassy marbles from the top of the head,
but amount to little more than light-sensitive nobs. The ocelli are simple eyes that bees use to
orientate themselves towards the sun. Located in a triangular shape are 2 dorsal ocelli and
1 central ocelli.
The ocelli are incapable of forming images; they appear to play
a more limited role in tracking patterns of light intensity and polarization. Bees use ocelli to
navigate, particularly at dusk.
The real action takes place inside the 2 enormous compound eyes that frame and dominate a bee's
face. Each one contains over 6,000 facets that constantly beam their individual views of the world
to the brain. The brain knits together all those pictures into a single, wide-angle composite image.
Because the eye is rigid, its focal distance if fixed and quite short. The makes anything seen from
afar look like a highly pixilated blur. Flowers, nest holes, fellow bees and other objects only
resolve into sharp focus up close - within a few inches.
The myopic view of the world may seem limiting, but bees compensate for this with an
extraordinary ability to sense motion. Every compound eye facet is individually hard-wired, from
lens to brain, so that anything moving through the bee's field of vision sets off a whole cascade of
reactions.
Even the smallest motions stimulate hundreds of facets, all of which glimpse that moving object
from a slightly different angle. The result is a hyper-awareness that allows bees to unconsciously
calculate speed, distance and trajectory.
The compound eyes of male bees are much larger as their primary goal in life is to spot motion —
the streak of an eligible female bee passing by on her nuptual flight.
Bees can’t see the color red, but they can see in the ultraviolet spectrum which is especially
important to bees as it helps outline landing zones on flowers.
Bees have hairy eyes.
Honey bees have hairy eyes, although this is not true for all species of bees. The hairs may have
clever function. The spacing between the hairs on a honey bees
eyes is the same as a single grain of dandelion pollen – a highly common pollen collected by bees.
The honey bee is able to keep the pollen suspended above its eye, allowing for its legs
to comb through the hairs and collect particles when the honey bee is grooming. Honey bees are
able to carry a significant proportion of their own body weight in pollen due to these cleverly
placed hairs.
Comparison of human
and bee eyesight.
Humans see light in wavelengths from approximately 390 to 750 nanometers (nm). These wavelengths
represent the spectrum of colors we can see. Bees, like many insects, see from approximately 300 to
650 nm. That means that bees can’t see the color red, but they can see in the ultraviolet spectrum
(which humans cannot).
Ultraviolet vision is especially important to bees as these ultraviolet patterns often outline
landing zones, pointing them towards the part of the plant containing nectar
and pollen.
Bees can also easily distinguish between dark and light – making them very
good at seeing edges. This helps them identify different shapes, though they can have trouble
distinguishing between similar shapes that have smooth lines – such as circles and ovals.
Have you ever wondered how bees fly? Scientists first
realized that bees seem to flout the laws of mathematics in the 1930s.
Bees can learn faces, add and subtract and even process the concept of zero. In a new study
they studies bees to understand how they acquire information.
To talk of bee tongues is to vastly oversimply the complex apparatus that makes up bee
mouthparts. They vary considerably in size and shape, depending on the need.