Honeybees Learn to Understand the Concept of Zero

Grasping the concept of zero is a sophisticated cognitive milestone. For a long time, scientists believed only humans and a few highly intelligent vertebrate animals could understand “nothing” as an actual numerical value. However, groundbreaking cognitive experiments prove that honeybees can also comprehend the mathematical idea of zero, completely reshaping how we view insect intelligence.

The Cognitive Challenge of Zero

To understand why this discovery is so important, we have to look at what zero actually means. Zero is not simply an empty space or a missing object. It is a mathematical concept that places the idea of “nothing” onto a numerical continuum. It is a specific quantity that sits below one.

Human children usually do not fully understand this concept until they are around four years old. Historically, human civilizations took thousands of years to invent a symbol for zero. In the animal kingdom, researchers have only documented a true understanding of zero in a highly exclusive group of animals. These include chimpanzees, rhesus macaques, dolphins, and an African grey parrot named Alex.

Until recently, scientists assumed that understanding such an abstract mathematical concept required a massive, complex brain. The discovery that a honeybee can process this same mathematical rule challenges everything biologists thought they knew about brain size and cognitive power.

The Groundbreaking Experiment

The primary study proving this capability was conducted by researchers at RMIT University in Melbourne, Australia. Led by researcher Scarlett Howard and associate professor Adrian Dyer, the team published their findings in the journal Science in June 2018.

To test the bees, the researchers set up a very specific visual training exercise. They created white cards featuring varying numbers of black shapes. The shapes were different sizes to ensure the bees were actually counting the objects rather than just judging the total area of black ink on the page.

The training process involved the following steps:

The team separated the bees into two groups.
They trained the first group to always choose the card with the greater number of shapes.
They trained the second group to always choose the card with the fewer number of shapes.
When a bee made the correct choice, it received a drop of sweet sucrose solution.
When a bee made the incorrect choice, it tasted a drop of bitter quinine.

Over time, the bees learned the rules. The group trained to pick the smaller number would consistently choose a card with two shapes over a card with four shapes, or a card with one shape over a card with three shapes.

Testing for Nothingness

Once the bees mastered the basic rules of greater than and less than, the researchers introduced the ultimate test. They presented the bees with two new cards. One card had a single black shape. The other card was completely blank.

Keep in mind that the bees had never seen a blank card during their training. They had only been trained to compare cards containing between one and four shapes.

The bees in the “lesser number” group flew up to the displays, observed the options, and consistently landed on the blank card. They did this 64 percent of the time. By choosing the empty set, the bees proved they recognized that zero is a quantity that is mathematically smaller than one.

To confirm the bees truly understood zero as a number on a continuum, the researchers looked for a psychological phenomenon known as the numerical distance effect. In humans and primates, it is much easier to tell the difference between two numbers that are far apart (like zero and six) than two numbers that are close together (like zero and one).

The honeybees displayed the exact same cognitive trait. When the researchers asked the bees to choose between zero and six shapes, they were highly accurate. When asked to choose between zero and one shape, their accuracy dropped slightly, showing they had to think harder to compare the closer numbers.

Brain Size Versus Processing Power

What makes this discovery truly remarkable is the physical size of a honeybee brain. A human brain contains approximately 86 billion neurons. A honeybee brain contains fewer than one million neurons and is roughly the size of a sesame seed.

Despite having 86,000 times fewer neurons than a human, the honeybee can process an abstract mathematical concept. This proves that a massive brain is not a strict requirement for advanced intelligence. Instead, it suggests that the architecture of a brain and the efficiency of its neural connections are much more important than raw size.

This realization has major implications for the future of technology and computing. Computer scientists are highly interested in how a tiny insect brain can perform complex tasks using very little energy. By studying the neural networks of honeybees, engineers hope to design better, highly efficient artificial intelligence algorithms that require far less processing power than current models.

Why Do Bees Need to Count?

It might seem strange that an insect needs to understand advanced math. However, surviving in the wild requires constant problem-solving. Honeybees are expert foragers. They travel miles away from their hives to locate nectar and pollen, and they must safely navigate back home.

Scientists believe that a basic understanding of numbers helps bees track landmarks. A bee might need to remember to fly past three trees and turn left after the second bush to find a specific flower patch. Furthermore, assessing the amount of nectar available in different areas requires the ability to compare quantities. While understanding the exact concept of “zero” might not be a daily requirement for a bee, the underlying numerical intelligence that makes it possible is deeply tied to their survival.

Frequently Asked Questions

Do bees actually count? Yes. Cognitive experiments show that honeybees can count up to at least four. They can also perform very basic arithmetic, such as adding or subtracting one from a given number of objects when trained with color-coded cues.

How many neurons does a bee have? A typical honeybee brain contains just under one million neurons. For comparison, a fruit fly has about 100,000 neurons, a mouse has 71 million, and a human has roughly 86 billion.

What other animals understand zero? Before the discovery in honeybees, scientists had proven the understanding of zero in chimpanzees, rhesus monkeys, vervet monkeys, dolphins, and certain highly intelligent birds like the African grey parrot.

Why is the concept of zero so difficult to grasp? Zero is difficult because it requires an animal to represent something that is absent. The brain must take the physical reality of “nothing” and assign it a mathematical value that interacts logically with physical quantities like one, two, and three.