Syrian hamsters are solitary animals and should always be kept with one hamster per cage, yet it seems that pet stores often violate this rule. It is not unusual to see groups of hamsters apparently living in peaceful coexistence at pet stores, but there's a reason you should not do this at home.
Most hamsters seen at pet stores are quite young, and even Syrian (also known as golden) hamsters can be kept together at a young age. Usually, by the time these rodents reach about 8 to 10 weeks old, they must be separated before serious fighting, sometimes to the death, occurs. Trying to keep adult Syrian hamsters together is just asking for trouble.
Even if you don't see your Syrian hamsters in a battle, it's a good bet that keeping them together causes stress, which shortens their lifespans. A well-tended Syrian hamster can live 3 to 4 years in your home, but only 2 1/2 to 3 years in the wild.
Pet Store Pretense
It is also worth mentioning that just because they appear to be OK at the pet store at any given moment, that doesn't mean there haven't been or won't be problems. If the hamsters you see in a single cage at the pet store are older, it's likely that those that show battle scars or evidence of a fight have already been taken out of the cage. It's also probable that with younger animals, the hamsters have been separated into same-sex groupings. That prevents unwanted pregnancies and territorial fights.
Female Syrian hamsters are aggressive toward males when the females are not in heat. Even when she is in heat, the female at best will tolerate the male.
Syrian Hamsters at Your Home
Once you bring your Syrian hamster home, give it lots of space. They are territorial and enjoy room to run, play, and burrow. At a minimum, the cage for a single hamster should be at least 2 feet by 1 foot and at least 12 inches high. Don't be afraid to go bigger. Your pet will thank you.
It's also a good idea to give your hamster separate toys. While some cages come with toys and compartments built in, they take up space that your hamster might prefer to spread out in.
If you have more than one golden hamster in your home and put their cages close together, make sure neither hamster can escape its cage. Syrian hamsters like to gnaw and you don't want your pet to get out. Don't be concerned if your hamster ignores its roommate–your pets are absolutely content to live a solitary existence. That doesn't mean a Syrian hamster shouldn't be handled by humans. They enjoy contact, but usually at night and may bite if awakened from a nap.