# Honeybees Can Add and Subtract, Study Finds

After discovering that honeybees understand the concept of zero, scientists tested the insect’s ability to spot gains and losses.
Western honeybee carrying pollen. Image: Muhammad Mahdi Karim

Honeybees can perform mathematical calculations such as addition and subtraction, according to a study published Wednesday in Science Advances.

A team led by Scarlett Howard, a postdoctoral fellow at the University of Toulouse who goes by the handle “the beesearcher” on Twitter, devised an experiment that demonstrated that these insects could recognize gains and losses.

“Given that honeybees and humans are separated by over 400 million years of evolution, our findings suggest that advanced numerical cognition may be more accessible to nonhuman animals than previously suspected,” said the authors.

So how do you give honeybees a math test?

Howard’s team conditioned 14 bees to associate the color blue with addition and yellow with subtraction. This was done with an appetitive-aversive (reward-punishment) method, meaning the bees received a sugary food reward when they selected the right color and a bitter-tasting quinine liquid when they were incorrect.

The bees were exposed to an initial sample that displayed one to five shapes in either blue or yellow. They were then were trained fly into a “decision chamber” that contained two different display options. The bees were expected to recognize greater quantities in blue addition trials and smaller quantities in yellow subtraction trials.

In the addition trials, one of the two blue displays contained one more shape than the initial sample—the correct answer. The other display showed a number that was equal to or fewer than the starting sample.

For instance, say the bee first looked at a sample that had two blue shapes printed on it. Once it was in the decision chamber, it might be met with one display with three blue shapes while the other had one blue shape.

The reverse was true for the subtraction trials.

The bees became progressively better at the test and selected the correct answer 60 to 75 percent of the time, over 100 trials.

The fact that the bees were able to learn how to complete these puzzles adds to the previous evidence that they are capable of grasping advanced numerical concepts.