Yes, I know this is a couple years old. But, I somehow missed it first time round.
In 2009, neurophysiologist Johanna Meijer set up an unusual experiment in her backyard. In an ivy-tangled corner of her garden, she and her colleagues at Leiden University in the Netherlands placed a rodent running wheel inside an open cage and trained a motion-detecting infrared camera on the scene. Then they put out a dish of food pellets and chocolate crumbs to attract animals to the wheel and waited.
Wild house mice discovered the food in short order, then scampered into the wheel and started to run. Rats, shrews, and even frogs found their way to the wheel—more than 200,000 animals over 3 years. The creatures seemed to relish the feeling of running without going anywhere.
The study “puts a nail in the coffin” of the debate over whether mice and rats will run on wheels in a natural setting, says Ted Garland, an evolutionary physiologist at the University of California, Riverside, who was not involved in the work. More importantly, he says, the findings suggest that like (some) humans, mice and other animals may simply exercise because they like to. Figuring out why certain strains of mice are more sedentary than others could help shed light on genetic differences between more active and sedentary people…
On average, the backyard mice she and colleagues observed ran in 1 to 2 minute stints, roughly the same duration as that seen in lab mice, they reported online…in the Proceedings of the Royal Society B. The team also set up a second wheel in a nearby nature preserve of grassy dunes and attracted a similar crowd of enthusiasts.