The queen’s odor bouquet, however, contained many other scents. To be sure they’ve got the right one and that others are not involved in reproductive suppression, the researchers tested what happens when the queen herself is gone, but her royal molecule stays. It turned out the scent alone kept the subjects in check just as well as the real queen did.
Game of thrones
The team started by taking mating pairs out of a colony away from any queen. Under such conditions, mole rats usually start breeding within four or five weeks. When the team sprinkled their cages with isopropyl myristate daily, though, the animals did not breed—the compound reliably prevented pregnancy. Once the contraceptive effect was confirmed at the individual level, Lewin’s team extended this experiment to the whole colony scale.
Removing a queen from an established colony normally sets off the mole-rat version of Game of Thrones. The strongest females fight against each other, often to the death, until a single winner emerges as the new queen. When the researchers removed the queen and dosed the colony with isopropyl myristate every day for three months, there were no attempts at coup d’etat. “Everything was peaceful,” Lewin says. “We had no fights. We had no females emerging as reproductive queens. The molecule was acting as a super contraceptive keeping them all sexually repressed.”
To Lewin, these results show that naked mole-rat biology is more closely tied to insect eusociality than scientists expected. Queens in honeybee colonies and other eusocial insects use pheromones to keep worker daughters from developing ovaries. “It’s a relatively simple mechanism that explains a relatively complex behavioral trait,” Lewin says.
What we are still not sure about is whether in this shape or another it appeared somewhere else in the mammalian evolutionary tree. Because secreting isopropyl myristate is not something exclusive to naked mole rats. Humans do that too.
“Isopropyl myristate has been detected in the breast secretions of lactating human mothers, though its function there is unknown,” Lewin says. “This molecule or similar molecules may have effects on reproduction in species other than naked mole rats, maybe even including humans. We just don’t know that”.
Nature, 2026. DOI: 10.1038/s41586-026-10772-5
