https://www.cnet.com/news/scientists-show-bees-can-solve-simple-math-problems/

"Our study provides an important building block for understanding how brains can evolve an ability to do maths," says Adrian Dyer, a co-author on the study from RMIT University.

To test the buzzers' ability to perform arithmetic, the team used a three-chambered maze shaped like a Y, training bees to enter through a hole into a small chamber where they would see their first stimulus: blue or yellow shapes on a plain, grey background. The number of shapes varied between 1 and 5 and the colour of the shapes told the bee whether it needed to add one (blue) or subtract one (yellow) from the initial number. The bee then flew into a subsequent chamber which presented both a correct option and an incorrect option.