Ants Fail to Add Numbers of Same Elements Seen Consecutively

The workers of the ant Myrmica sabuleti have been shown to be able to distinguish different numbers of elements and to be able to add them if seen side by side, at the same time. They have thus a concrete concept of numbers and of adding. It remained to know if they have an abstract mathematical concept of numbers and of their addition. For tempting answering this question, we presented, to M. sabuleti workers, two numbers of elements (circles) not placed side by side but making an angle, the ants having thus to move for seeing the one then the other of the numbers of elements. After 3, 6, 9 and 12 of such training days, the ants were tested in front of the two numbers of elements as well as of their correct sum and their sum plus one element. The ants responded essentially to the two numbers of elements they saw during training, and far less to their sum and sum plus one element. The ants have thus a basic, concrete concept of adding numbers of elements they see. Young human children (3 to 6 years old) have such a concrete concept of numbers and of adding, but they acquire in several months, through learning, an abstract mathematical concept of these notions and of related ones.