[cheryl j (OP)]

I heard a great story on the CBC today. I have no idea how one gets funding for something like this, but a researcher found that not only caged mice, but wild mice like running on wheels. They left wheels out in a natural surrounding attached to a camera and found that wild mice would come and run in the wheel. Not just mice, but moles, voles, frogs, and slugs. (I have no idea how frogs or slugs would do that. I would like to see the video.)

http://www.theguardian.com/science/grrlscientist/2014/may/21/wild-mice-exercise-wheels-behaviour-stereotypy-neurosis