Hamsters are among the most commonly kept companion rodents but are routinely housed in cages far too small for their welfare, despite their natural behavior of running up to 10 km per night and requiring substantial territory.
Hamster welfare is characterized by a massive gap between commercial product standards and animal welfare requirements. The hamster wheel, far from being an optional toy, is a necessity for an animal evolved to run distances that no commercial cage can provide. Behavioral indicators of inadequate space — stereotypic bar-chewing, repetitive circling, aggression — are so common in commercially kept hamsters that they are normalized by owners who do not know that better conditions are achievable. Deeper bedding allowing natural burrowing, wheel access, and substantially larger enclosures are the welfare-determining factors. The difference in welfare between a poorly and well-kept hamster is enormous and achievable at modest cost.