Numerosity ability is an important biological trait. We examined this trait in the ant Myrmica sabuleti over sixteen experimental works. A summary of the first nine works has been already published, and we provide here a summary of the last seven works. During these last-mentioned studies, we successively showed that ants natively possess a number line, acquire the notion of zero through experiences, have their counting ability only slightly affected, depending on the characteristics of the elements to count, can acquire single symbolism, can learn several symbols at the same time, can add up using learned symbols and can learn a symbol for zero and use it to add. Four of these abilities correspond to potential problems of numerical competence in humans. Humans have natively a number line, but rarely, they may suffer from not having it, what then reduces their skills in mathematics. Humans have to acquire the notion of zero in the course of their life, but this notion is not always correctly taught to children. Also, after having been learned to add and subtract using a concrete representation of numbers, human children should learn calculating using different representations, and finally without using any concrete representation. Humans can easily acquire symbolisms, and this ability should be employed without delay over the children’s education. No doubt that more knowledge on animal numerosity ability will be acquired in the future, maybe to be related to human numerical competence.