Perhaps you live in the kind of household that likes to divide up the chores. You take the dishes, while someone else does the trash. If so, you are not so far off from the habits of a naked mole-rat, according to a new study.
The findings, published Wednesday in the journal Science Advances, show that individual naked mole-rats perform specific duties for their colony, including digging, transporting garbage, and cleaning the “toilets.” The study reveals that the rats undertake a form of task allocation that helps the colony function more efficiently, according to the researchers.
“Overall, our findings reveal the distinct roles of breeders and the remarkable behavioral diversity among nonbreeders, underscoring the complexity of naked mole-rat social organization,” they write.
An elusive social system
Naked mole-rats (Heterocephalus glaber) are small, nearly hairless rodents that live underground in large colonies. These colonies can be made up of several hundred individuals and stretch across miles of tunnels.
These colonies are eusocial, meaning they exhibit the highest level of organization in animal social behavior. In eusocial systems, a single female and a few males produce all the offspring, while most other individuals are put to work. Bee colonies are another common example of an eusocial system. Remarkably, naked mole-rats are one of only two known mammal species to exhibit this social structure.
Much like bees, scientists have found that naked mole-rats perform a variety of tasks, but it was unclear whether individuals consistently stick to specific jobs or are more flexible. The answer to this question has long eluded researchers due to the challenges of monitoring an entire underground colony over long periods of time, but a team led by Masanori Yamakawa of Kumamoto University in Japan found a way.
Tracking an underground workforce
Yamakawa and his colleagues developed an automated radio-frequency identification (RFID) tracking system to monitor 102 naked mole-rats across five captive colonies for 30 days.
Each colony assigned specific functions to different “chambers,” typically including a nest, a toilet, a garbage, and six additional chambers. The nest was where individuals huddled and rested, the garbage was where they deposited waste such as excess food or dried feces, and the toilet—well, you get the picture.
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