Readin’, ‘Rithmetic and… Honeybees? Learning to Add, Subtract and Read Numbers in the Hive

In a first for insect kind, a series of studies has found that simple honeybees can not only perform basic arithmetic—adding and subtracting the number one from a number provided to them—but they can also learn how to read symbols to learn what the numbers involved in the equation are to begin with. Although this capability has been demonstrated in primates and birds in the past, this is the first time insects, even ones with a fraction of the brain power of a human, have demonstrated this level of cognition.

The experiments consisted of a simple Y-shaped maze, with a “decision chamber” that branched off into two other chambers, one with a sugar water reward, and the other with a bitter-tasting quinine solution to signal an incorrect answer.

At the entrance to the maze, each bee was presented with an array of elements that consisted of between one to five shapes that represented a number that was the key to the equation for that given iteration of the experiment. The shapes would be either blue or yellow: blue indicated that the bee needed to add one to the number it was presented with on the way into the chamber to solve the puzzle, while yellow indicated that subtraction was required to find the right path to the prize. The sides of the maze that the sweet and bitter solutions were in were changed at random, so that the bees wouldn’t simply get used to going to one side or the other to find the sugar water.

For instance, if the bee was presented with an image of two blue squares when entering the maze, this meant that the equation to be solved was “2+1”; the two options in the decision chamber could then be, for example, one blue square on one side, indicating an incorrect answer of “one”, or three blue squares on the other, correctly completing the equation, “2+1=3”.

Despite having less than one tenth of one percent of the number of neurons that a human has (960,000 vs 86 billion), these well-schooled bees managed to choose the right path a little over two thirds of the time (64 to 72 percent) after learning the maze’s mathematical language, far better than the fifty percent chance the researchers would expect to see if the insects were simply guessing which chamber held the reward.

While we might take such simple mathematical tasks for granted, the process of adding or subtracting one from a given number requires two levels of mental processing: first, our bee needs to be able to comprehend the numerical value of the symbols being used, and the second process requires the bee to manipulate that numerical attribute in its working memory, or on the fly, as it were, to then perform the arithmetic needed to produce the answer, once again in working memory.

This illustrated that the humble honeybee is capable of combining the functions of both symbolic learning and simple arithmetic, despite having brains that would presumably provide only a very limited processing capacity.

This experiment was later repeated by the same research team, except this time instead of the number of shapes representing the intended numerical value, the bees were presented with invented symbols that represented the numbers; instead of three circles symbolizing the number three, “3” would now be represented by a singular shape, for instance an upside-down letter “T”.

The numerical representations from the previous experiment were still used—alternately at the maze entrance or in the decision chamber—with the new symbols being used opposite the numbered shapes. After learning this new symbolic language, the bees had a roughly 75 percent success rate in solving the equations.

“We take it for granted once we’ve learned our numbers as children, but being able to recognise what ‘4’ represents actually requires a sophisticated level of cognitive ability,” explains vision scientist Adrian Dyer of RMIT University in Australia. “Studies have shown primates and birds can also learn to link symbols with numbers, but this is the first time we’ve seen this in insects.”

But the bees apparently couldn’t learn the process in reverse: if an individual bee had learned using a symbol at the entrance and the numbered shapes in the decision chamber, it was unable to learn how to solve the equation if it was presented with a numbered shape before encountering the symbols in the decision chamber once inside the maze.

“This suggests that number processing and understanding of symbols happens in different regions in bee brains, similar to the way separate processing happens in the human brain,” said zoologist Scarlett Howard of the Université Toulouse III – Paul Sabatier.

“Our results show honeybees are not at the same level as the animals that have been able to learn symbols as numbers and perform complex tasks.”

Nonetheless, the experiment’s findings offer key insights into the development of the self learning capabilities of artificial intelligence, and that this self-learning can be accomplished with a limited amount of processing power. It also offers insight into our own neurology, and how different cultures came to independently develop their own mathematical systems throughout history.