Full disclosure: I think rats are fascinating creatures. A lot of people are grossed out by rats, which I can understand, but I owe my interest in rats to my brother and a book called Rats: Observations on the History and Habitat of the City’s Most Unwanted Inhabitants, by Robert Sullivan. In the book, Sullivan observes a pack of New York City rats in a garbage-filled alley near Wall Street for a year. (He calls this activity “going ratting.”) He also talks to exterminators, sanitation workers, and everyday New Yorkers about their experiences with the rodents. About a year ago, my brother, Matt, let me borrow his copy of the book, which he said was “awesome” and made him want to “go ratting.” Considering that my brother lives in New York — Rat Capital of the World — he has ample opportunities to go ratting, if he wanted to. Because one thing you’ll learn if you decide to read Rats is that if you’re in New York, you’re usually in close proximity to rats anywhere you go. Viral videos back that up.
I was hesitant to read it — an entire book about rats? Really? — but thanks to Matt’s glowing review, I gave it a shot. It’s seriously interesting stuff learning about the history of rats and their behaviors. I also learned that rats are a lot smarter than most people think. So when I saw a couple of rat-related One Health stories online today, I knew I would end up blogging about them.
A new study at the University of Chicago has found that empathy isn’t just a human trait: rats feel each other’s pain, too. The researchers placed two unrelated, same-sex rats in a cage for two weeks, but put one in a Plexiglas box inside the cage. The trapped rats were distressed and making noises. Three-quarters of the time, the free rat would help the trapped one escape. From the Science magazine article linked above:
But what motivated the rats in the first place? To find out, the Chicago team kept up daily tests on the rodents that had learned how to open the container. Each free rat kept liberating its trapped cagemate for a month, which ruled out simple curiosity as a motivation. What’s more, the free rat would liberate its cagemate even when the trapped animal exited into a separate cage, which showed that the free rat wasn’t simply seeking the reward of schmoozing with its friend. The rats also freed trapped cagemates even when they had the option of bumping open an identical container and obtaining five chocolate chips for themselves, which showed that their motivation to help was on par with their desire for a tasty treat. In fact, half of the time they even shared chips by leaving one or two for the trapped rat, the team reports online today in Science.
They shared chocolate with each other! How cool is that?
The study’s findings will lead researchers to a better understanding of the psychology of empathy in people, and whether it’s a result of nature or nurture. While some scientists may doubt that rats are capable of feeling this kind of emotion, the study’s senior author and professor of psychology and psychiatry at the University of Chicago, Jean Decety, said that’s narrow-minded.
“There’s no reason to think that only humans are pro-social and have empathy,” he said.
If you want some more insight into this study, Washington State University has posted an interview with Jaak Panksepp, the university’s chair of animal well-being science and professor of veterinary and comparative anatomy, pharmacy and physiology. Dr. Panksepp was not involved in the University of Chicago study, but he has done extensive research on non-human animals and emotions. He did a study about laughter in rats, and you can watch a short video of him called “Rats Laugh When You Tickle Them.”
See what I mean about rats being fascinating?