Scientists, researchers and animal rights advocates have argued over the years about the nature of mice running on wheels in their cages. Rights activists claim the running is a form or neurotic behavior brought about by living in the confines of a small cage. Some researchers, on the other hand, have suggested that the mice seemed to like, or enjoy running on the wheel, and even exhibited unhappy behavior if a wheel was removed. To learn more, Meijer and Robbers decided to carry out a very simple experiment—they set up a running wheel in their backyard, then used an infrared camera to capture on tape how animals in the wild would respond.
To get things, rolling, so to speak, the researchers also laid down some food near the wheel to attract some animals. They also put the wheel inside an enclosure with a small entrance way to keep large animals from knocking the wheel on its side. Examination of the film showed that a lot of animals found the wheel, climbed on and began running on it. Granted, most of the animals were mice, but the camera also caught frogs, rats, shrews and even slugs. The frogs didn’t actually run, they simple hopped form one side to the other causing the wheel to roll back and forth, and the slugs appeared to arrive on the wheel by accident. Still, the results were so encouraging that the team set up another wheel and camera in a nearby dune area not accessible to the general public.
In all the team recorded over 200,000 animals using one or the other of the wheels over a three year period. The main runners were mice, some of which jumped on, ran for a while, jumped off, then jumped back on and ran some more. One mouse ran for an incredible 18 minutes.[WATCH THE VIDEOS HERE](http://phys.org/news/2014-05-animals-wild-wheel-choice-video.html)