Wheel running in the wild.
A lot of experiments with mice measure their running on wheels in their cages. Some had worried that the running was a symptom of captivity rather than a natural behavior, invalidating many experiments. So, between 2009 and 2013 researchers placed running wheels in the wild with cameras trained on them. It turns out mice were naturally into it! Also, so were “shrews, rats, snails, slugs [and] frogs.” ~ learn more