When I was a kid, I had a hamster that spent an inordinate amount of time climbing to the top of her cage and falling off, bouncing into her wheel multiple times on the way down. Thanks to the work of Rebecca Meagher and Georgia Mason from the University of Guelph I now think I know why. They found that caged animals get bored if they don't have enough variety in their environments. At least, that's true for mink.
Mink are small carnivores from the same family as weasels, ferrets and otters. The researchers divided 29 mink into two groups. All the mink were housed in identical wire cages with nest boxes. However, the mink fortunate enough to be in the enriched group (E) could access a second, much larger cage full of a variety of interesting objects and running water. The non-enriched group (NE) had no such tunnel access to goodies.
After seven months of acclimating to their respective living conditions, the mink were presented with some novel stimuli. These could be aversive (like a puff of air), neutral (a scented candle) or pleasant (for male mink, female feces made the list—go figure). Interest in food treats was also evaluated. The NE mink were far less reluctant to investigate even negative stimuli than the E mink, who presumably had better things to do with their time. The non-enriched mink also ate considerably more treats. All in all, the NE mink showed classic signs of boredom.
Although it can be dangerous to extrapolate across species, I wouldn’t be at all surprised if this result held true for other caged mammals. I guess we should be mixing it up a little more for our small pets.Rebecca K. Meagher, & Georgia J. Mason (2012). Environmental Enrichment Reduces Signs of Boredom in Caged Mink PloS ONE : doi:10.1371/journal.pone.0049180