Influence of Shape, Color, Size and Relative Position of Elements on Their Counting by an Ant

It was previously shown that workers of the ant Myrmica sabuleti can discriminate small numbers of elements during testing when these elements were identical to those learned during training. Here we examine if this numerosity ability still subsists if the shape, color, size or location of the elements (dots) to count are modified between training and testing. We found that the ants’ counting ability was not significantly affected by changing one of these features although a somewhat lesser ability was observed. Among the changes, it was that of the relative position of the elements which disrupted the most the ants’ counting ability, followed by a change of their size. A change in the color or the shape affected the least the ants’ counting. These impacts of feature changes in the learned cues on the ants’ counting can be explained by characteristics of the visual perception of the species as well as by its behavioral ecology.