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.
Stephanie Pappas, Live Science Contributor
Stephanie interned as a science writer at Stanford University Medical School, and also interned at ScienceNow magazine and the Santa Cruz Sentinel. She has a bachelor's degree in psychology from the University of South Carolina and a graduate certificate in science writing from the University of California, Santa Cruz.