Wheel in the Wild
Lab mice and rats run on wheels in captivity, but researchers wanted to know if the behavior is natural. To find out, they set out exercise wheels in wild areas.
Although the wheel looks like a cage, animals can come and go freely. [Read More About the Wild Wheel-Runners]
A wild mouse hops on one of the outdoor exercise wheels and takes a spin.
Frog on a Wheel
It wasn't only mice who appreciated the exercise wheels. Frogs, shrews and voles used the equipment, too.
Slug on the Wheel
Even slugs and snails enjoyed taking the exercise wheels for a spin.
Lead researcher Yuri Robbers (center) and associates set up an outdoor exercise wheel.
Live Science newsletter
Stay up to date on the latest science news by signing up for our Essentials newsletter.
Stephanie Pappas is a contributing writer for Live Science, covering topics ranging from geoscience to archaeology to the human brain and behavior. She was previously a senior writer for Live Science but is now a freelancer based in Denver, Colorado, and regularly contributes to Scientific American and The Monitor, the monthly magazine of the American Psychological Association. Stephanie received a bachelor's degree in psychology from the University of South Carolina and a graduate certificate in science communication from the University of California, Santa Cruz.