Naked mole rats — known for their protruding teeth and wrinkly scrotum-like appearance — are highly social rodents with a wide variety of vocal dialects, a new study has revealed.
On top of that, these rats exhibit one of the most human-like traits of all: xenophobia.
According to a paper entitled “Cultural transmission of vocal dialect in the naked mole-rat” published in the journal Science on Friday, naked mole rats live in multigenerational colonies under the earth. Each colony can consist of up to 300 rodents, with a queen at the top of the hierarchy who serves as the only mating female. Specific roles are assigned to all other rats in her domain, including soldiers that protect the entrance to a colony and fight to defend the queen.
In order to communicate in this sophisticated social structure, naked mole rats have developed “distinctive colony dialects.”
In the study, researchers from the Max Delbrück Center for Molecular Medicine in Germany and the University of Pretoria in South Africa recorded over 36,000 of these vocalizations made by 166 rats in seven different colonies. They discovered that the dialects in each colony are not only distinct, but also change with each queen.
“We actually think that one of the ways in which the queen maintains her control is to make sure that everyone is ... rigidly adhering to a certain dialect,” said Alison Barker, one of the authors of the study, in an NPR interview. “And so that becomes, perhaps, a readout for conformity within the colony.”
When a queen dies, a mole rat colony can devolve into full-on warfare to determine the next queen.
“The dialects before the queen was gone were much more cohesive — they all spoke with a very similar dialect,” Gary Lewin, another scientist who worked on the paper, told CNN. “As soon as the queen was gone there was a period of anarchy, and everyone started speaking a little more variably.”
Lewin added that mole rat colonies are “incredibly xenophobic,” and dialects can serve as an easy way to recognize foreigners. Postnatal rats brought into foreign colonies will learn the dialect of their adoptive home, but adult intruders are another story.
“If a mole rat comes from a different colony, within minutes, they are recognized and usually killed,” Lewin said.
Violence in the mole rat world, in other words, is something right out of “Game of Thrones,” which the researchers used as inspiration for naming the different colony dialects — for instance, the chirps of “Dothraki mole rat colony.”