Hamsters are among the most commonly kept small pets and among the most commonly housed inadequately, with typical pet store cages being far too small for these energetic, wide-ranging animals.
Hamster welfare failure is ubiquitous and largely invisible. The traditional small plastic cages sold in pet stores prevent the extensive running, burrowing, and ranging that hamsters are adapted to perform. Hamsters in inadequate housing develop bar-chewing, repetitive running, and other stereotypies indicating chronic frustration and stress. Adequate housing requires a minimum floor space of approximately 450 square inches with deep burrowing substrate, an appropriately large wheel, and enrichment. The gap between what pet stores sell as adequate and what welfare science recommends is enormous.