How to Introduce Hamsters to Each Other

Hamsters tend to be more solitary than social, but a careful and conscientious hamster owner may be able to introduce two or more dwarf hamsters to one another successfully under very carefully managed and controlled circumstances. Never introduce Syrian hamsters.

Syrian hamsters, also known as golden hamsters, are among the most common types of pet hamster, and they are not social animals. The American Society for the Prevention of Cruelty to Animals recommends that you never put any other hamsters inside the cage with a Syrian hamster, regardless of breed. The introductions will not go well, and the shared living arrangement can lead to one of your hamsters being attacked, injured or even killed by the other. Do not ever let your Syrian hamster loose with any other hamster.

Dwarf hamsters, though, another type of hamster, are considered to be social, but they still may fight if not introduced properly. If you are going to introduce dwarf hamsters to one another, make the introduction while the animals are juveniles. Introduce only same-gender dwarfs to one another unless you are specifically looking to breed hamsters. Introducing males and females tends to lead to rapid reproduction.

The key to a successful introduction is to allow the hamsters to meet and get used to one another within a safe environment.

Make introductions in a fresh cage that neither of the hamsters has recently occupied and that has been scrubbed clean of any scents. Even dwarf hamsters are territorial; they tend to attack when they feel their space is being intruded on by a newcomer.

Ideally, use two clean cages to introduce your hamsters. One of the cages should be significantly smaller than the other so you can place it inside the larger cage. Each cage should have its own food, water and toys.

• Place one hamster inside the smaller cage and one inside the larger cage and leave them there for an entire day. They should not have the ability to do more than touch noses with one another. This arrangement will allow them to get used to each other's scent and presence.
  
• Swap the hamster from the smaller cage into the larger cage and the hamster from the larger cage into the smaller cage. This ensures neither can get territorial about the spaces they are occupying. Leave them in place for an entire day.
• Continue swapping the hamsters back and forth in the cages for at least four days until they appear to be comfortable with one another and you see no signs of aggression.
• Remove the smaller cage and place both hamsters in the larger cage. Make sure you continue to maintain two sets of all supplies so the hamsters will not fight over food, water or toys.
• Supervise your hamsters carefully. Dwarf hamsters need time to get to know one another, especially when you are just beginning the introductions. Remove them from the cage and return to the beginning of this process if they display aggression or get into a fight.

If your hamsters are behaving in an aggressive manner during or after introductions, separate the animals and try to reintroduce them later. Aggressive hamster behavior is indicated by various actions:

• Hissing
• Chasing
• Baring teeth
• Yawning
• Biting
• Growling
• Attempting to attack each other

In some cases, you may find that the hamsters will never get along and simply cannot be together in the same environment.