Based on insights from multiple reliable sources, housing hamsters together is generally discouraged. Below is a detailed breakdown of the reasons and considerations:
I. Hamsters’ Innate Solitary Nature
1. Strong Territorial Instincts
Hamsters are classic solitary animals. In the wild, they defend their territories fiercely—often through biting and aggressive behavior—and this instinct remains intact even in domestic settings.
Even littermates (baby hamsters from the same mother) will turn on each other once they reach adulthood, as their territorial drives kick in.
Pet stores may house hamsters together, but this is only possible because the cramped space temporarily suppresses their territorial instincts. Such conditions cannot be replicated in home environments, where the urge to claim territory often reemerges.
2. Risks of Co-Habitation
Fatal Fights: There have been cases where Syrian hamsters (also called golden hamsters) and dwarf hamsters, when housed together, attacked each other fatally within just 2 hours. Severe injuries—such as torn fur, broken limbs, or deep bites—are common even in non-lethal fights.
Stress-Induced Sudden Death: Long-term stress from constant territorial threats can cause hamsters to develop irregular heart rhythms, loss of appetite, or even sudden death, as their bodies cannot cope with prolonged anxiety.
Spread of Infectious Diseases: Different hamsters may carry parasites (e.g., mites) or bacteria. Housing them together increases the risk of cross-infection, which can lead to skin issues, digestive problems, or other illnesses.
II. Special Cases and Controversies
1. Rare Successful Co-Habitation Examples
In extremely rare cases, same-breed male and female hamsters may live together temporarily— but only with strict preparation: using a “dating cage” (a divided enclosure for initial introduction), providing a very large space with multiple hiding spots, and monitoring their interactions 24/7. Even then, conflicts can arise without warning.
Hamsters raised together from a very young age (e.g., Roborovski hamsters, sometimes called “公婆鼠”) have a lower chance of attacking each other. However, this does not eliminate risk entirely—territorial disputes can still break out as they mature.
2. Common Misconceptions
“A big enough cage will prevent fighting”: Even in extra-large enclosures, hamsters’ territorial instincts persist. They may still mark areas as their own and attack intruders, regardless of space size.
“Opposite genders will get along”: Outside of mating season, male and female hamsters are just as likely to fight as same-gender pairs. Additionally, once a female hamster becomes pregnant, she will aggressively drive the male away to protect her future litter.
III. Scientific Housing Recommendations
1. The Single-Hamster-per-Cage Rule
Each hamster should be housed in its own cage. The minimum recommended size for a hamster cage is a 47cm basic enclosure—this provides enough space for exercise, nesting, and feeding without triggering territorial stress.
If you want your hamsters to “interact” without risk, place their cages next to each other. This lets them see and smell one another without physical contact, satisfying their curiosity safely.
2. Breeding Management
If you are breeding hamsters, separate the male and female immediately after mating. Leaving them together can result in the female attacking the male, or even the mother hamster eating her own pups due to stress from the male’s presence.
For a more visual understanding of the potential risks of co-housing hamsters, you can watch the following video demonstrations:
Conclusion: Housing hamsters together carries life-threatening risks. The safest and most humane practice is to keep one hamster per cage.