Another version of the maze, which was used by scientists, is a comb of 15 end points. The further the bait is from the entrance, the more time the scout needs to describe the path to the foragers. But if you place a bait on any branch more often, then the ants begin to use this branch as a new point of reference.
If branch number 10 is often used, then a little more than 10 times are spent to describe the path to 11 branches — that is, ants describe the path as “10 + 1”. And exactly the same result in time shows a twig 9 - that is, "10-1". This is reminiscent of the Roman system of calculus - X, XI, IX. So scientists have proven that ants are able to add and subtract.