The popular early 2000s manga and anime Hamtaro centered around the titular Hamtaro, a hamster who would meet up with his hamster friends the Ham-Hams in their special hamster clubhouse and have cool hamster adventures. Bad news, anime fans. If the show were more realistic, Hamtaro would murder each Ham-Ham he encountered in order to have the clubhouse all to himself.
It turns out hamsters, especially Syrian hamsters, are super mega territorial. While it’s not uncommon to see hamsters caged together at pet stores, it’s because hamsters in stores are usually really young. Once hambos hit about 8 to 10 weeks of age, you have to keep them apart or they will fight it out until one or both are dead, like those guys with switchblades who strapped their wrists together in the “Beat It” video. Even if they don’t fight, close proximity between adult hamsters will cause enough stress to significantly shorten their life spans. The only time adult Syrian hamsters should be together is when they’re mating, basically, but even then it’s an uneasy truce that is short-lived at best. If you have multiple Syrian hamsters, you have to keep them in separate cages and they should have their own toys.
Not all types of hamsters are insufferable solitary hermits, though. Dwarf hamsters can get along with same-sex roommates if they’re paired together from a young enough age. But even this is unreliable. They’re just grumpy old coots, man. Loners, Dottie. Rebels.