Mice like to 'Wheel' it Just for Fun

At the end of the day, Mice just want to have fun, too.

A recent study conducted by researchers at Leiden University Medical Center in the Netherlands showed that even mice in the wild would run on an exercise wheel--for physical fitness and for fun.

"When I saw the first mice, I was extremely happy," said Johanna H. Meijer, one of the researchers from the university, via The New York Times. "I had to laugh about the results, but at the same time, I take it very seriously. It's funny, and it's important at the same time."

For the study, researchers picked wheels that were enclosed, presenting small animals with the opportunity to use them, while simultaneously allowing larger animals to knock them over. Motion sensors and automatic video cameras were also used to capture close to 12,000 snippets of video, several years later.

Findings showed that mice accounted for 88 percent of the wheel-running events, with one to 18 minutes spent per wheel. Other animals--including frogs--accounted for less than 1 percent of interaction with the wheel.

As previous studies have suggested that wheel-running may be driven by stress or anxiety, Gene D. Block, chancellor of the University of California, Los Angeles, who was not involved in the study, said he believes that this research suggests that wheel-running is "some type of rewarding behavior," instead.

However, not everyone is so certain. According to Mark Bekoff, a professor of ecology and evolutionary biology at the University of Colorado, he said he believes that the study showed that though wheel-running is voluntary, caged mice may be more likely to run due to the stress of confinement.

More information regarding the findings were released online Tuesday via the Proceedings of the Royal Society B.