If you want to give your boy hamster a female companion, you have to follow certain protocols. Otherwise you could create a dangerous situation. Hamsters can be territorial little critters and, while they may not pose much of a threat to you, they can do serious damage to one another. The breed, sex and place of introduction are all important things to consider when introducing two hamsters, especially ones of opposite sex.

Let your hamster go on living the bachelor life if he is of a breed that doesn’t appreciate company. Syrian hamsters, namely, are territorial; they simply refuse to live with others. If you want to give him a companion, the pair will have to live in separate cages.

Place your female hamster in the male’s cage and monitor them as they interact. Generally, females are more aggressive than males, so putting a female in with a male makes him less of a threat — he is in his own territory, not invading hers. The hamsters may fight a little at first, but if it seems excessive or one-sided, remove the female and cage her separately.

Set up a new, fresh, never-used cage for the hamsters to share. Sometimes, when one hamster is introduced to another in an existing habitat, territorial fighting can prevent them from cohabiting. If the environment is neutral ground, however, it makes this type of fighting somewhat less likely. Hide a few small treats in the cage and introduce both hamsters at the same time. By the time they’re done hunting treats, they’ll have become used to one another.