Naked mole rats are accustomed to acidic environments that even humans cannot tolerate, reveals a new study by the University of Illinois in Chicago.

A team of researchers studied the naked mole rats that are native to east Africa and live in burrows where the level of carbon dioxide is at a higher level which cannot be sustained by any other mammals, even humans.

These rats are rodents that are tiny and hairless resembling walruses. They are more like some species of insects - they live in groups and have the queen as well as worker groups. While the queen breeds and broods the young ones, the worker rodents dig burrows for the entire group to live and also find food resources to eat, according to a report in National Geographic.

For their study, the research team monitored the naked mole rats along with laboratory rats, mice and other naked mole rats that prefer to live in comfortable conditions, in an ambience where the air in some areas contained acidic fumes.

The rats were allowed to move freely inside the cage. Experts compared the behavior of the naked mole rats with the other species. They found that the mole rats were tolerant to the acidic environments exposing themselves freely to the acid fumes, while the other species preferred to avoid the areas with acid fumes.

Whenever a mammal is exposed to acidic fumes in the air, the nerve cells in the nose get activated and arouse the trigeminal nucleus which has three branches of nerves that are responsible for sensory and motor actions. The nerves educe the physiological and behavioral responses which help in protecting the animal (like keeping away from acidic fumes), the researchers explained.

They measured a protein known as c-Fos, a marker that helped in finding if the nerve cells were activated. Experts noticed that there was no such activity in naked mole rats, whereas the trigeminal nucleus was activated in other species.

Naked mole rats' adaptability to such acidic environments while living in burrows has made the species to become tolerant of effects from the fumes, the experts pointed out. They hope the study will help in finding ways to lessen the pain in humans.

"Studying an animal that feels no pain from an acidified environment should lead to new ways of alleviating pain in humans," said Thomas Park, professor of biological sciences at UIC and lead study author, according to ScienceDaily.

The findings of the study are published in the journal PLOS ONE.