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Bee Eyes

Bees are fascinating creatures that rely heavily on their eyesight to navigate their environment and carry out important tasks. Their eyes are uniquely adapted to help them find flowers, communicate with other bees, and avoid predators. In this article, we’ll explore the science behind bee eyes and how they contribute to the survival of these important pollinators.

How Many Eyes Do Bees Have?

Bees have five eyes. They consist of two large compound eyes that are located on the sides of their head, and three smaller eyespots (ocelli) in the middle. These eyes are essential for the bees to survive, as they allow them to see a wide range of colors, shapes, and sizes. Without their keen eyesight, bees would struggle to navigate their environment and find food sources.

Bee Eyes Anatomy

The bee´s head is the center of sensory perception. Nearly everything bees use to sense their outside world is either a part of the head or connected to the head, like the antennae for example. Unlike human single-lense eyes, bee eyes are round, smooth, and glassy. The larger compound eyes located on the side of the head contain thousands of tiny lenses (ommatidia). Each ommatidium contains a photoreceptor cell that detects light and sends signals to the bee’s brain. The arrangement of these ommatidia allows bees to see in multiple directions at once, giving them a wide field of vision.

Additionally, honeybee eyes are sensitive to ultraviolet light, which helps them locate flowers and navigate their environment. Overall, the unique anatomy of honeybee eyes plays a crucial role in their survival and ability to carry out important tasks.

What Color are Bee Eyes?

Bees typically have black eyes, but some species like the Blue Carpenter Bees have beautiful blue eyes, while those of the Silver Leafcutter Bees are pale green.

What Are Compound Eyes Used For?

Honeybees have two large eyes (compound eyes) on the sides of their head that can detect objects from different angles. At first glance, these eyes look like two solid, plastic-like orbs. However, upon closer inspection, they are composed of thousands of tiny lenses (ommatidia). Each ommatidium contains a photoreceptor cell that detects light and sends signals to the bee’s brain.

Each ommatidia has a hexagonal-shaped face called a ‘facet’. These adjoining facets create the surface of the compound eye. When bees look through their compound eyes, they see many images all around them. This is because each ommatidia points in a slightly different direction. Like tiny cameras, each ommatidia collects light and sends signals to the bee’s brain. This allows bees to see a mosaic of different images that work together to create a larger image.

These facets are essential for the bee to gather the information it needs to navigate through its environment, such as finding flowers and avoiding obstacles. Each facet plays a crucial role in the bee’s ability to see and interpret its surroundings. It gives bees an amazing field of vision, and to detect movement with incredible accuracy, helping them to detect potential predators while foraging. By combining the information from each lens, bees can see a wider and more detailed picture of their surroundings.

In fact, honeybees can see ultraviolet light, which helps them navigate and find flowers with nectar. The structure of their eyes is just one of the many fascinating adaptations that make honeybees such important pollinators in our ecosystem.

Do Bee Eyes have 360 degree vision?

No, but their compound eyes enable them to have very good peripheral vision. The hexagonal facets of the ommatidia cover most of the bee’s head, allowing them to see in many directions at once. However, there are some areas that are blocked, such as the area behind the bee’s head.

What Are the Ocelli Used For?

Ocelli or ´little eyes´

Honeybees have three small eyes called Ocelli (lat. “ocellus” = “little eye”) located on on the top of their head. They are positioned in a triangle between the antennae, with two located on the dorsal side and one in the center. These three small dots make up the unique arrangement of the honeybee’s eyes. The ocelli are not easily noticeable unless observed closely.

These simple eyes function differently from human eyes. Instead of forming images, they primarily sense light helping them to detect UV markers from the flowers, and to navigate by using the position of the sun. It enables bees to easily locate the horizon and horizon line, which is especially important at the beginning and end of each day, and to land safely to collect nectar.

The ocelli are small, with each eye containing one single lens that is used to detect light intensity and direction. Although the ocelli can detect light, they cannot see shapes. This means bees can sense if they are approached from above by a predator. While their exact function is not fully understood, they are believed to aid in detecting sunlight and general light intensity, which helps with the bee’s navigation during flight.

Honey bees are known for their hard work during the day, but some bees have adapted to forage at night. These “crepuscular” bees have larger ocelli, which are simple eyes that can detect changes in light intensity. This adaptation helps them navigate and collect resources during the low-light hours of dawn and dusk.

Do Some Bees Have Larger Ocelli Than Others?

The size of a bee’s eyes can vary depending on the species and their activity patterns. Honey bees and bumblebees, for example, have larger eyes to help them navigate during the day. However, some bee species are more active at dawn and dusk, and therefore have larger ocelli to help them see better in low light conditions. So, the size of a bee’s eyes is closely related to their daily routine and the environmental conditions they face.

Honeybees have a unique ability to see in low light conditions, which allows them to collect pollen and nectar from flowers that bloom at night. This is particularly important in warm regions such as deserts, where the bees may prefer to forage during the cooler nighttime hours.

What Are the Differences Between Ocelli and Compound Eyes?

Picture centre – 3 Ocelli Eyes, Left and Right either side – Compound Eyes

The much larger compound eyes are located on the side of a bee´s head. They have with thousands of tiny lenses (ommatidia). In contrast, the ocelli are located in the middle of the head in form of a triangle, and contain only one lens.

Both types of eyes have a distinct job function. Compound eyes have multiple facets that give bees a greater peripheral vision and accurately detect movement. This is helps them to detect potential predators while foraging.

Whereas the ocelli only detects UV light but no shapes, allowing bees to navigate and find suitable food sources.

How Bees see Colors and Patterns

Honeybees have a unique ability to see colors and patterns invisible to the human eye. They can see ultraviolet light to locate flowers and navigate their environment. In addition, they can see polarized light, which allows them to detect patterns in the sky that help them navigate.

Humans can see a wide range of colors in the light spectrum with a wavelength from 390 to 750 nanometers (nm). In contrast, bees have a narrower visibility, with a wavelength of typically between 300 to 650 nm. This means they cannot detect red light and are able to view ultraviolet rays which humans are unable to detect.

Furthermore, bees excel at distinguishing between dark and light, which is a vital tool for recognizing shapes in their environment. The arrangement of the ommatidia in their eyes also allows them to see patterns and shapes with great detail, making them excellent at recognizing familiar landmarks and identifying other bees.

However, they do have trouble distinguishing between shapes that have smooth edges like circles and ovals. In addition, bees have an enhanced ability to see polarized light in comparison to humans. This helps them orient themselves better when navigating the landscape and can also help them locate food sources more.

The Role of Polarization Vision in Honeybee Navigation

Honeybees have a unique ability to see polarized light, which empowers them to navigate their environment with great precision. Polarized light is light that vibrates in a single plane, rather than in all directions like normal light. This type of light is produced when sunlight is scattered by the atmosphere, creating patterns that are invisible to the human eye.

Honeybees use these patterns to navigate, particularly when flying long distances. By detecting the polarization of light, honeybees can determine the position of the sun, even on cloudy days, and use this information to navigate towards their destination. This ability is crucial for honeybees, as they need to be able to find their way back to the hive after foraging for food.

Are Bees’ Eyes Hairy?

Interommatidial hairs of honey bee eyes

Yes, honey bees have small hairs (interommatidial hairs) that grow on their eyeballs. These hairs sprout out from between the ommatidium that make up the compound eyes of insects. This fascinating adaptation plays a crucial role in the bees exceptional flying abilities. They can detect changes in wind speed and direction to determine the optimal time to take off and navigate their environment with precision. This is particularly important when navigating back to the hive in windy conditions as they help the bees stay on course and avoid getting blown off track.

Scientists also believe the hairs serve a practical purpose keeping the lenses clean, so the bees can see clearly and navigate their environment with precision. While more research is needed to fully understand the function of these hairs, they are just one of the many fascinating adaptations that make honeybees such remarkable creatures.

Before taking flight, honeybees can be seen meticulously cleaning their eyes and antennae. This grooming behavior serves to remove any pollen particles that may have become stuck to their fuzzy bodies, ensuring that they have clear vision and can navigate their surroundings with ease.

Are all Bee Eyes the Same?

Variations of Compound and Ocelli Eyes in Apis Mellifera

No, a study of Apis mellifera compound eye variations in the number, size, and spacing of facets between bee castes varied. This is also true across various other bee species.

Queen bees have fewer but larger facets in their compound eyes compared to workers and drones. The average number of facets per eye is 4034 facets in the queen bee, 5145 facets in workers, and a staggering 9355 facets in drones.

Another difference between worker bees and drones is the size and spacing of the facets. Workers have higher facet density and smaller inter-ommatidial angles (IOA) than drones. This suggests they may require sharper vision to navigate and find food sources. Drones have a lower facet density but larger IOAs, which is more useful for detecting movement and landmarks during mating flights.

These differences in compound eyes can be linked to different roles and behaviors within the hive. While queen bees simpler visual system rely more on chemical and tactile cues to maintain their position of power, workers and drones use their compound eyes to carry out specialized tasks.

Drone Bee Eyes

Honeybees have compound eyes that are made up of thousands of tiny lenses called facets. These facets are attached to ommatidia, which are responsible for processing visual signals and sending them to the bee’s brain. This complex system of lenses and ommatidia allows honeybees to see a wide range of colors and patterns, making them excellent navigators and foragers.

Drones come across as the lazy members of the colony because of their ´small´ work contribution within the hive. However, their eyesight is quite impressive. They have larger eyes than worker bees, allowing them to better navigate and locate potential mates during their mating flights.

The ability to see clearly is crucial for drone honey bees, as they rely on their vision to locate virgin queens in flight. Without sharp eyesight, they would not be able to fulfill their important role in the hive’s reproductive process.
Honeybees have unique eyes that allow them to navigate and mate high up in the air outside of their hives. These mating areas are specifically designed for honeybees and are known as drone congregation areas.

Bumble Bee Eyes vs Honey Bee Eyes

Image by Journal of Apiculture, V. B. Meyer-Rochow(A) and (B): Scanning electron micrographs of the compound eyes of bumblebee (A, top) and honeybee (B, bottom) at identical magnifications. Note the dense cover of interommatidial hairs on the eye of the honeybee. (C) and (D): The scanning electron micrographs show the facets covering the eye of the bumblebee (C, top) and that of the honeybee when the hairs have been brushed off (D, bottom).

Although both species have 2 compound eyes and 3 ocelli, there are a few key differences between honeybee eyes and bumblebee eyes:

  • Bumblebees have slightly larger eyes than honey bees and an average of about 6,000 ommatidia.
  • Honeybees can see a wider range of colors than bumblebees. Honeybees can distinguish many different colors, including some in the ultraviolet spectrum, while bumblebees have a more restricted color vision.
  • Bumblebees have a smoother surface in their compound eyes and lack the interommatidial hairs of honey bee eyes
  • Honey bees and bumble bees both spend a lot of time in the bright sun. Bumblebee eyes exposed to similar levels of UV-radiation as honey bees seem unaffected. It remains unclear whether the resistance to UV-induced damage is genetic or whether they build up UV-resistance during the summer.

Can Bee Eyes Measure Flight distance and Speed?

How can bees fly miles away from their hive to forage and find their way back home without getting lost? Researchers discovered that bees use their eyes to measure distance. They keep track of the “optic flow” across their eyes as they fly. By flying through tunnels with different patterns, scientists found that bees perceive longer distances when there is more visual information in their eyes. They also adjust their flight speed to maintain a constant level of optic flow. This helps them navigate through visually complex environments without crashing. These findings have even inspired new strategies for controlling flying drones using visual cues.

Ability to detect Motion

Honeybees have incredibly fast visual processing abilities. While humans can only perceive movements that last longer than 1/50th of a second, bees can detect movements that occur in just 1/300th of a second.

Bees possess the most rapid color vision of any animal, enabling them to quickly locate nectar and pollen sources in even the shadiest places. Their ability to detect color is almost 5 times faster than humans.

This is due to their compound eyes, which are made up of thousands of tiny lenses that work together to create a mosaic-like image. The bees’ brains then process this information at lightning-fast speeds, allowing them to navigate and communicate with each other effectively. This sensitivity to movement allows bees to navigate through fields of flowers, even when they are swaying in the slightest breeze.

The importance of Bee Eyes in Pollination

Vision is vital for honeybees as they feed on nectar and pollen, and therefore play a crucial role in pollination. Their unique eyesight is a key factor in their ability to find flowers at a distance. Although they can pick up hues of scents the flowers release, this only works when they are close. It could be possible that bee vision evolved to become attuned to flowers, however, history shows that it is more likely that flowers have evolved to attract insect pollinators. (See History of Bees)

By detecting the polarization of light, honeybees can see flowers in a way that humans cannot. This allows them to identify flowers that are rich in nectar and pollen, and communicate this information via the waggle dance to other foragers in their colony.

They also use their eyesight to navigate inside the flowers, allowing them to collect pollen and nectar efficiently. Without the unique eyesight of honeybees, pollination would be much less efficient, and many plant species would struggle to reproduce.

Unfortunately, the bees eyesight is under threat from a variety of factors, including habitat loss, pesticide use, and climate change. These threats can impact the ability of honey- and other bees to find flowers, communicate with each other, and avoid predators.

To address these threats, conservation efforts are underway to protect honeybee habitats, reduce pesticide use, and promote sustainable agriculture practices. By protecting honeybee eyesight, we can help ensure the continued health of our ecosystems and food systems.

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