Ants Can Add Up Using Learned Numeric Symbols

The workers of the ant Myrmica sabuleti have been shown to be able to add numbers of elements after having seen them simultaneously, side by side, during training, and to be able to acquire single as well as multiple symbolism. It was here examined if these ants could make additions using learned symbols. In fact, after having learned the required symbols during a first conditioning, the ants could, thanks to a second conditioning, carry out operations 1 + 1, 1 + 2, 2 + 2 and 3 + 1 by using the quantities of elements presented as well as their corresponding symbols. This ability results from the ants’ learning of the correspondence between symbols and numbers of elements by an operative conditioning, and from their ability to add up two quantities viewed simultaneously. A comparison of the ants’ score when adding elements and when adding their corresponding symbols suggests that the use of symbolism may represent some facility for the execution of simple arithmetic operations, as is the case in higher animal species.