Honey bees have a total of five eyes, three on the top of their head and one on either side. These eyes have different roles, with the two compound eyes helping the bees find food and avoid predators, while the simple eyes help them navigate.
How many eyes does a honey bee have?
Most of us will be able to picture a honey bee in our minds. They are, after all, an iconic species, which has become more famous still due to their connection in media with the decline of pollinators. Therefore, if asked the question ‘how many eyes does a honey bee have’ in a pub quiz, you would probably answer confidently that they have two. And you’d be wrong.
The honey bee does have two large, prominent eyes on the sides of its head. But it also has an additional three on top of its head, between the other two. You’d be unlikely to notice these three smaller eyes unless you were looking at an up-close photo, and even then, you might miss them.
The two larger eyes are what is known as compound eyes. These are common amongst insects and are made up of lots of smaller lenses built up into one big eye. These individual lenses are known as ommatidium. The honey bee workers have around 5,500 of these lenses in each eye, while the drones have approximately 10,000. This may be because the drone needs better eyesight to locate a queen to mate with as she flies swiftly through the swarm of his competitors.
Each one of these lenses picks up and processes light separately, focusing it into a point as it travels through the lens, then sending it down through the various parts of the ommatidium to be processed into electrical signals which inform the brain what the eye is seeing.
As well as the lenses, the honey bees eyes are covered in a series of small hairs. They grow out from between the ommatidium. The exact reason for these hairs is still unclear, but the most common theory is they are there to help gather pollen and keep it away from the lenses. Honey bees regularly brush all the pollen they’ve collected off their bodies and into their pollen sacks, which includes brushing it from their eyes.
The three smaller eyes are known as ocelli. These are single-lens eyes rather than compound eyes. They are arranged in a triangle between the bee’s two compound eyes, on top of their head. It is thought these aid the bee in navigation, so it can use the sun’s position to guide it.
How good is a honey bee’s eyesight?
If we compare a honey bee’s eyesight to a human’s, there’s a curious mixture of being worse in some respects and better in others. This is mainly because different information is more critical to a bee than it is to us.
Firstly the bee sees a different range of colours to us. Unlike the human eye, the honey bee’s eye can pick up ultraviolet light. This proves incredibly useful as flowers give out secret messages to their bee visitors using the ultraviolet colour range, something that completely passes us by. However, they cannot see red.
Within their ommatidium, the bee’s have a series of receptors that pick up ultraviolet light, green and blue. By comparison, we have blue, red and green receptors in our eyes.
A bee’s sight is also much more granular than ours; the human eye can see around 100 times the detail of honey bees. However, where the bee outstrips us is in its ability to see movement. The bee’s eye can pick up 150 images a second, whereas we can do no more than 30.
Such granular but fast-moving vision comes in highly useful for a small insect flying quickly through the landscape, looking to pick up splashes of colour from flowers and avoid the snapping beaks of birds.
How do bees see flowers?
Because of the different range of colours, how a bee can see flowers actually looks entirely different for them than they do to us. One of the main differences is the ultraviolet markings the flowers have. These are like a bullseye guiding the bee into the centre of the flower. This is important so the bee can access the pollen and nectar quickly, and the flower can be properly pollinated.
As well as the ultraviolet guiding system, flowers also attract bees in with an electric charge. As the bees fly through the air, they build a positive charge, while the flowers are negatively charged. This guides the bees towards the flowers. It also helps the pollen be drawn into the bee’s fur from the flowers. Think of it as your hair being pulled up towards a balloon with static electricity.
Many flowers also inform bees if they have already been pollinated, by changing colour, such as the centre of forget-me-nots, which turn from yellow to white when they have been pollinated. This saves the bee time and means the plant can encourage insects to visit flowerheads that haven’t already been pollinated.
What about the rest of the bee’s head?
As well as the five eyes, the bees head has a mouth and two antennae.
The antennae act as critical sensory organs and particularly help with touch, taste and smell perception. Its mouth, like most insect mouths, is made up of a series of sections. They have mouthparts for chewing and sucking, mandibles for cutting things up or biting, and a proboscis for sucking up liquids.
So do bees have bad eyesight or good?
Often with species, there is no direct comparison, each being adapted perfectly to their individual needs. We can say for sure that the bee’s eyes are both fascinating and highly specialised. We may never be able to see precisely what the world looks like through their eyes, but it’s certainly very different from how it looks through our own.