Wasko, K., Acklin, C. J. 2013. Fresh façades for rodent homes: Revisiting enrichment naturally. Enrichment Record 16, 9-11.

Currently, enrichment consists of a variety of plastic toys to promote natural behaviors, but why use artificial devices when you could use natural materials like the animals experience in their native environment? ... From these three tests it appears that our initial assumptions were correct: you get what you pay for! Two out of three basic evaluations clearly showed that a natural environment is the optimal choice, extending benefits not only for the animals but for the experimental results as well. Even the activity wheel, though not always the popular choice, showed similar trends despite a lack of statistical significance. We believe that this effect may largely be the result of the luxury bedding materials added to the natural caging environment; with more layers of bedding, the rats were able to practice their natural burrowing instinct, not to mention get an incredible night's sleep. Surprisingly, in most cases, we observed that synthetic enrichment did not provide any noticeable benefits, which is very different from what we expected to see, since this type of enrichment has proven to be beneficial in the past. This is a classic case of modern construction versus natural design. Our evaluations demonstrate that even the most common enrichment devices fail to provide the animals with necessary stimuli. The plastic devices we used are the same ones used in many major laboratory facilities worldwide to decrease stress levels and enhance exploration and cognition. If this enrichment truly is not helping to accomplish that goal, then standard enrichment protocols may have to be reviewed and modified. Using natural materials instead of synthetic devices could be the key to effective environmental enrichment. Without it, scientific research may pay the price. Be sure to make an appointment with your natural enrichment realtor soon - you may be pleasantly surprised.