Numerical cognition in honeybees enables addition and subtraction

TLDR

Many animals can perform basic number tasks, but complex symbolic arithmetic has only been demonstrated in a few nonhuman vertebrates. This numerosity display requires bees to acquire long‑term rules and employ short‑term working memory. Honeybees can learn blue and yellow symbols to add or subtract one element from a group in free flight, solving novel problems and suggesting that advanced numerical cognition may be more common across species than previously thought.

Abstract

Many animals understand numbers at a basic level for use in essential tasks such as foraging, shoaling, and resource management. However, complex arithmetic operations, such as addition and subtraction, using symbols and/or labeling have only been demonstrated in a limited number of nonhuman vertebrates. We show that honeybees, with a miniature brain, can learn to use blue and yellow as symbolic representations for addition or subtraction. In a free-flying environment, individual bees used this information to solve unfamiliar problems involving adding or subtracting one element from a group of elements. This display of numerosity requires bees to acquire long-term rules and use short-term working memory. 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.