A rare ant species in Japan has no males or workers – only queens, researchers have found. These ant queens live parasitically in the nests of another ant species and reproduce asexually to create clone queens to take over other nests.
The parasitic ant, Temnothorax kinomuraiis the “first known species with only queens,” said Jürgen Heinzea biologist at the University of Regensburg in Germany, and co-author of a new study describing the findings.
But there are also parasitic queens that infiltrate the colonies of other species and take them overoften making the workers serve them and raise their offspring until their own breeding has taken over.
Keiko Hamaguchia biologist at the Kansai Research Center in Kyoto, Japan, and her colleagues have investigated T. kinomuraiwhich has been found in only nine locations in Japan. The ant was suspected to operate differently and produce only queens without any workers or males, but that was not known for sure.
Young T. kinomurai queens invade the nests of a related species, Temnothorax macorastabs the host queen and the most aggressive workers who try to stop the coup. If the takeover works, the surviving workers raise the alien queen’s young.
“T. kinomurai need the host workers for feeding and brood care and cannot produce offspring without them,” Heinze told LiveScience via email.
To find out what’s going on, Hamaguchi’s team assembled six colonies powered by T. kinomurai queens and kept them in nest boxes in the laboratory. From these colonies they raised 43 offspring, none of which were males, according to examination of the genitalia, or workers, which would be smaller. All were queens.
When presented with new potential host T. makora colonies, seven of the 43 offspring, who had never mated, succeeded in coup attempts. This is in line with the typical high failure rate of the risky business of founding a parasitic colony. The seven queens produced a total of 57 offspring, all of whom were also queens. The findings were published on 23 February in the journal Current Biology.
Queens of some ant species can clone themselves through asexual reproductionknown as parthenogenesis. Other ants exploit social parasitism, hijacking the workforce of unrelated colonies to raise their own offspring.
“Yet, until now, no species had been shown to combine both strategies, despite the intuitive evolutionary logic behind such a combination,” Jonathan Romiguieran evolutionary biologist at the University of Montpellier in France who was not involved in the work told LiveScience via email.
“Considering there are over 15,000 ant species out there, this is quite unusual,” added Daniel Kronauera biologist at The Rockefeller University in New York who was not involved in the study.
The benefits of sexual and asexual reproduction is normally finely balanced, he said. Asexual reproduction can allow an organism to maximize its own genetic contributions to the next generation by producing genetically identical daughters, and asexual species can often outcompete their sexual counterparts because they do not have to invest energy and resources in finding mates and producing males.
But sexual reproduction produces genetically diverse workers, which can be beneficial to an ant colony when it comes to it pathogen defense and division of labour.
But given that T. kinomurai queens don’t produce workers anymore, those advantages have disappeared,” Kronauer told Live Science. “This could shift the balance in favor of asexual reproduction and ultimately the loss of males,” he said.
Hamaguchi, K., Kinomura, K., Kitazawa, R., Kanzaki, N., & Heinze, J. (2026). A parasitic, parthenogenetic ant with only queens and no workers or males. Current Biology, 36(4), R123–R124. https://doi.org/10.1016/j.cub.2025.11.080
