How to Introduce Pet Mice

Putting treats immediately into a cage with newly introduced mice may incite fighting.

Mice are social creatures and are believed to be happier and more active when kept in pairs or groups from an early age. However, according to the Rat and Mouse Club, even introductions between adult mice can be successful if done the correct way. A large, clean cage with an ample supply of toys can help improve the odds that the new cage mates will live in perfect harmony.

Things You'll Need

• Large cage or aquarium
• Multiple exercise wheels
• Clean bedding

Instructions

1. Remove the mice from their individual cages and clean one habitat out thoroughly, eliminating all scent from the environment. The mouse that previously lived in this cage won't smell his or her scent and will be less likely to become territorial. If possible, place food bowls and other items in different spots when reassembling the cage to further eliminate recognition.

2. Introduce the mice to each other on a neutral ground, perhaps within a play pen on the floor or in another never before used cage. The All About Mice website recommends placing a dab of vanilla essence on each mouse so they will all smell the same to each other. Let them thoroughly explore and become familiar with each other.

3. Place the new mouse, or the one that has not lived in the chosen cage before, into the clean and disinfected cage. Allow him or her to explore the new surroundings for a few minutes and then place the other mouse into the same cage.

4. Watch the mice and observe they interact with each other for at least an hour to make sure that they are not fighting with each other. According to the Fancy Mice website, keeping the cage in the owner's bedroom the night of the introduction can help keep tabs on the new cage mates during the evening, which is when mice are most active.

5. Allow the mice to continue to investigate their new territory. They may chase each other and get into non-threatening scuffles, which are normal. However, if biting gets out of hand and blood is drawn, remove the most aggressive mouse and allow him or her to calm down before trying the introduction again.

Tips & Warnings

• Groups of mice tend to get along best when they are related and paired at an early age. For this reason, a mother and her daughters will usually live together more peacefully than two unrelated female mice that are being introduced as adults.

• Rodents can be very aggressive attackers and will sometimes fight to the death. Observing the interaction of newly-introduced mice is crucial to their health and survival.

References

• Rat & Mouse Club of America: Can You Keep Male Mice Together?
• All About Mice: Introducing Mice
• Fancy Mice: What to Expect When Introducing Female Mice

Resources

• Pet Mice: Mice as Pets