Naked mole rats are truly loyal workers. Not only do they care for their queen's children, they also have to eat her feces to prepare.
The Strangeness Of Naked Mole Rats
These are unique creatures, even in the colorful variety of the animal kingdom. Naked mole rats are blind, furless burrowing rodents that hail from the eastern regions of Africa.
According to Phys.Org, these small animals are the only known mammal with a eusocial structure, which means only one female — a queen — produces all the offspring. All the other females are workers and are unable to reproduce due to underdeveloped ovaries. Since it's known that these subordinates care for the queen's offspring, there must be a mechanism that allows these females to exhibit maternal instincts.
In a new study from Japan published in the journal Proceedings of the National Academy of Sciences, researchers find out that the process involved in this is strange and innovative.
Eating Queen's Poop Found To Make Better Parents
It's well-established by previous research that naked mole rats eat their own feces. As the scientists tried to figure out what was behind the workers' parenting inclinations, they wondered whether naked mole rats also eat their queen's feces. This would allow the mother to pass on some of her hormones, so that the workers could enjoy her maternal impulses.
The team from Japan fed groups of female workers different types of pellets. One group was fed pellets with fecal material from a pregnant queen mole rat, another with fecal material from a queen that wasn't pregnant, a third group without fecal material, and a final one received pellets enhanced with the hormone estradiol. Estradiol is naturally produced by naked mole rat queens.
Results of the tests show that the worker naked mole rats that were fed the pellets with fecal material from the pregnant queen and those fed with pellets with estradiol were more attentive to the children than the two other groups. Those who consumed the pregnant queen's feces also showed a spike in estradiol concentrations.
"Because subordinates' responses to pup vocalizations were enhanced through the ingestion of nonpregnant queen's feces amended with estradiol, we concluded that estradiol is the substance that enhances their responses to pup vocalizations in naked mole rats," the authors wrote in the study. "Moreover, these results suggest that naked mole rats communicate the substance between the queen and subordinates through coprophagy."