A team of German neuroscientists from the Humboldt University of Berlin spent several weeks hanging out with rodents in a small room filled with boxes. They were playing human-vs-rodent hide-and-seek and found out the animals were surprisingly adept at the cross-cultural childhood game. They weren’t even given treats as a reward, rather, they were given attention in the form of friendly petting and tickles.A rat receives a belly tickle. (Reinhold, Sanguinetti-Scheck, Hartmann & Brecht/TNS)
The rats were having so much fun they actually jumped for joy and laughed – ultrasonic inaudible giggles to be precise. They were truly enjoying the fun of both finding their sneaky human companions and being caught by them. Although, if you ever end up playing with a rodent yourself and he giggles, you won’t hear it. Their mischievous giggles have to be picked up by scientific equipment because they’re too high-pitched to be detected by the human ear. The study has been published in the journal Science.
The players involved were six adolescent male rats and neuroscientist Annika Stefanie Reinhold. The room they played in was filled with hiding places made from different boxes. Before they began playing together, the researchers let the rats become accustomed to the space.
Impressively, they were able to learn that if they began the game inside a closed box, they were the seeker, while being in an open box meant they needed to hide. Each day that passed, the rats became stealthier, working out that opaque boxes make the best hiding places and checking spots where their two-legged rival had hidden before when seeking. They weren’t just playing for tickles too, they were actually motivated by the fun of the game.The experiment sheds light on the sophisticated sense of play in these tiny rodents and the complex mechanisms at work in their brains. (Reinhold, Sanguinetti-Scheck, Hartmann & Brecht/TNS)
Co-author Konstantin Hartmann told AFP:
When you work a lot with rats over the years, you see how intelligent these animals are and how social. But it was still very surprising to us to see how well they did.
Of course, the researchers were having fun, but there was more to this research than that. The study offered new insight into play behavior, and how it is an important evolutionary trait among mammals. It reveals how critical play is as part of cognitive development for adolescent mammals.
To really tap into this, they even attached microwires to the rats’ heads that recorded their brain activity, allowing them to identify which individual neurons were linked to specific game events. The information gathered from these recordings could be used in a future study to help answer a new question: “If play is restricted, would it affect neural development?”
Research like this really helps us better understand the importance of play. Do kids that play more become smarter? What about kids that are deprived of playtime, are they compromised? If they are denied the opportunity to have fun and play with others does it affect their mental development?
Aside from what these sort of studies can teach us about humans, they also shed light on the ethics of using rodents as objects of experimentation. As Hartmann told AFP:
I think, being aware of the cognitive abilities of an animal is really important. This type of research will also help other scientists to see in rats more than what you usually see when you just get the rat and use it for standard experiments, when you’re not aware of what these animals can do.