Candid Cuties! Photos of Wild Animals on Wheels

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.

Exercise Wheel

Although the wheel looks like a cage, animals can come and go freely. [Read More About the Wild Wheel-Runners]

Mouse Running

wild mouse runs on a wheel — (Image credit: Yuri Robbers)

A wild mouse hops on one of the outdoor exercise wheels and takes a spin.

Frog on a Wheel

frog running on an exercise wheel — (Image credit: Yuri Robbers)

It wasn't only mice who appreciated the exercise wheels. Frogs, shrews and voles used the equipment, too.

Slug on the Wheel

slug runs on an exercise wheel — (Image credit: Yuri Robbers)

Even slugs and snails enjoyed taking the exercise wheels for a spin.

Wheel Experiment

an outdoor exercise wheel setup — (Image credit: Yuri Robbers)

Lead researcher Yuri Robbers (center) and associates set up an outdoor exercise wheel.