Mouse Wheel Fun Run

Anthony and Jeff's debate about the joy to be found in running and exercise contuinues.  This time, Jeff has an article from the New York Times about a study which showed that mice will spend time on a running wheel, even when they don't have to.  When placed out in the woods, completely unattended, mice and other creatures would jump onto a wheel, and spend time running on it... for fun.  Is this the proof Jeff has always wanted, or are these just Anthony's alpha Brock mice?