Colonies of social Hymenopterans are characterized by numerous conflicts over reproduction between the workers and the queen(s). Though workers can exert an important power on the colony reproductive outcome by their control on brood development, queens frequently manipulate the workers or the larvae mediating chemicals to limit resource investment in sexuals. We conducted a field survey to analyze the production of sexuals in the ant Aphaenogaster senilis. The number of sexuals observed in more than 160 colonies excavated over three years was extremely male-biased, a general pattern in fission performing species. Interestingly, all females were found in nests that had apparently no queen. Males were also mostly produced in queenless nests. This marks a striking difference with the congeneric species A. rudis that reproduces independently, for which demographic data are available in the literature. We conducted a laboratory experiment in which we confirmed the inhibition of sexual production in queenright colonies of A. senilis. By separating a group of workers with larvae from the queen by a single (QL-SM) and a double mesh (QL-DM) we demonstrated that the queen signal is not volatile. These results suggest that fission procures workers a way to escape the queen inhibition of sexual production. We hypothesize that, by leaving the mother colony with a portion of brood, workers can rear a few new females, one of which will further head the new nest. During the time window between fission and colony take over by the new queen, the workers may also lay numerous haploid eggs developing into males.