The purpose of this article is to establish a clear distinction between the concepts of childhood and infancy; this distinction can allow us to observe through the study of biopolitics, the radical changes that differ Foucault's classical analysis regarding children to Agamben's reflections on infancy. In the line of Agamben's theory, the association of child-infancy does not have an adult-non-infancy reciprocal association; furthermore, the notion of infancy as a chronological stage that the child and/or the adult have both left behind depends not only on a social construction of childhood but also on an ancient Greek biopolitical production of life itself. This ancient concept of life contains the binarism of zoe/bios, nature/culture, animal/man that leads to an obscuring eclipse of the concept of human being as a form-of-life, characterized by the permanent update of infancy that functions as a link between this binarism. Since infancy has no chronological association, either historically or age-related, this essay aims to review the type of relation that both children and adults have with infancy.