Whether you are fond of bees or not, you have to admit that they are incredible little creatures. What might be most amazing about these essential animals are their abilities. Every animal is created with certain gifts and talents. Some are superb at swimming, while others may excel at camouflaging themselves or implementing other defense mechanisms. Others are exceptional at the hunt and chase. But can bees see at night? This question is more common than one might think.
Bees have several gifts that make them critical parts of our environment. First and foremost, they are the world's best pollinators. Bees pollinate over 80 percent of all flowering plants and crops on the planet. Scientists have labeled them as a “keystone” species for this reason. This means that without them the ecosystems that make up their habitat would die off and cease to exist.
Think of all the flowering plants in the world. We have tulips and roses, but there are also trees and crops to be considered. Watermelons, tomatoes, cherries, almonds, apples, coffee, chocolate, and more all have blooming flowers and therefore require pollination to bear fruit and pass on seeds to the next generation. While there are other insects and small animals, like birds and bats, that help with this specific job, bees do the most work. In the U.S. alone, bees pollinated about $19 billion worth of crops in 2010, while all the other pollinators combined contributed to about $10 billion in crops the same year.
However, it's difficult to see how these small insects accomplish so much in so little time every year. To figure this out, we need to look at the bee much closer. We need to see what they are made of and how they use what they have to fulfill one of the world's greatest needs. What special characteristics do they have that others do not? One theory is that they can see in the dark and therefore work longer than most other species. But can bees see at night? Are they nocturnal?
Some Background on Bees
Let's begin with what we do know of bees. They are small flying insects that are related to both wasps and ants. Bees are well-known for their pollination skills and the production of honey and beeswax, although not all species can produce these products. There are around 20,000 known species of bees in the world that have been broken down into seven biological families.
Bees are found within every habitat in which flowering plants also reside. That means bees live on every continent except for Antartica. About 30 percent of these species live within social colonies, such as the honeybee and bumblebee. The other 70 percent live solitary lives, building nests in holes in the ground or dying and decaying wood.
Bees can range in size from about 0.08 inches in length up to around 1 1/2 inches long. The most commonly found bee species in the Northern Hemisphere is the sweat bee. They are specifically adapted to feeding on nectar and pollen, the latter of which they also feed to their young.
The Senses of Bees
The key to a bee's sense of smell is pheromones, chemical substances released into the environment by an animal. The purpose of this to change the behavior or physiology in other animals within the same species. It's how they communicate certain aspects of their life, such as their readiness to mate, a threat and alarm, foraging defense, and more.
Bees can feel by touch through several parts of their bodies. The antennae are especially important and are exceptionally sensitive. This is why you will see bees cleaning their antennae with their front legs regularly. Within the dark halls of the hive, their sense of touch is critical. They use this sense to feel out areas and measure the dimensions of the cells when they are constructing the honeycomb and wax. Bees also use this sense to help them interpret the dancing of other bees in the hive.
The hairs on bees' bodies also help them feel. All flowering plants have electromagnetic fields that are used to advertise. Each different species of plant has a different field based on their distance from the ground and their shape. The hairs on a bee are sensitive to these fields. When the hairs come within close range of the flower, they bend towards the plant, causing the bee to feel its presence. The bees can then remember this field generated by the flower and associate it with food for future reference.
This is one of the most efficient ways that a bee communicates with other bees. They perform a choreographed dance to tell other bees of important information, such as the whereabouts of food, danger, or where another suitable home may be. This information is provided in exact dimensions and distances. Other bees can then find food sources and new homes easily based on what another bee communicated.
Bees have an excellent sense of sight, significantly better than that of humans. However, they see things very differently. For starters, they have five eyes instead of the two that we have. Three of these are small, simple eyes with only one lens, like ours. These ocelli, as they are called, are found in the center of the top of the bee's head. The primary purpose of the ocelli is to sense polarized, infrared and ultraviolet light. They are not capable of forming images, though; that task is delegated to the other two eyes. These are much larger compound eyes that cover much of the bee's face. The compound eyes are made up of thousands of different lenses that each take in a tiny portion of what is around them. The bee's brain then combines these small images like pixels on a TV to make a complete image.
Can Bees See at Night?
So can bees see at night? There are four families of bee species that are known to be nocturnal and can see at night. Most of these species of bees are found in tropical or subtropical regions of the globe. However, a few can be found in arid climates at higher altitudes. These bees can see better at night because their ocelli, the three small eyes on top of their head, are greatly enlarged. This means they can sense light much easier.
Many of them also have refracting compound eyes. This filters more light to each lens, so it's able to see in darker circumstances. It helps them to avoid danger and find food that may only be available in the dark of night. It is also thought that the bee's brain may lengthen the amount of time that the lens collects light before sending a signal. This combination might make it harder to see slight details of an image but would allow a bee to see something in very little light.
Many bees that are not known to be nocturnal can fly in the dark without these specialized eyes. While it may be true that their eyes are not enlarged and lack refracting capabilities, they can still see at night well enough to operate and get home. This also comes in handy when the sky becomes dark and overcast or in an area of poor lighting, such as inside the hive or nest. In these circumstances, the bees use their abilities to see ultraviolet and polarized light.
Bees see color and light completely different than we do. While we can see more color, they can see more light variations. This means that they can't see the color red, but it does mean that they can detect ultraviolet light. This is helpful to bees because most flowers and plants are designed with ultraviolet light-absorbing pigments. These pigments create a pattern on flower petals that direct where the pollen and nectar can be found. A human eye can't detect this, but if you look at one with a UV lens, you will see that the center of the flower is much darker and more vibrant than the rest. Different flowers appear brighter or darker based on the amount and quality of the nectar produces. Bees can see this, and it tells them which flowers to visit and collect from. Ultraviolet light can pass through clouds, so bees can still pick up this light and know where to go in darker conditions.
Bees can also detect polarized light, which moves in one direction. When air molecules from the atmosphere scatter photons, they create a highway of polarized light. Bees can detect this light movement in patterns and use it like a GPS. It is what guides them every day. However, they don't need the sun to do this. Even when it's dark and gray, bees can still detect this polarized light and follow it to where they need to go.
The answer to the question “can bees see at night,” does not have a definitive answer. It is both a yes and a no. While they cannot see as we do, bees can see certain things at night. Bees can pollinate the world's crops because of their amazing abilities. There is not one skill that makes them better than other pollinators that complete the same task, but several. Bees navigate using spatial memory, building their own map. Between being able to see and detect ultraviolet light and polarized light, as well as the use of their other senses, they know exactly where they are going both day and night.