It sounds like you're asking about a real-life scenario, possibly about hamsters or other small rodents.
It's very important to remember that introducing multiple mice to a cage can be risky.
* Some mouse breeds are naturally solitary and will fight.
* Even friendly mice can become aggressive if their space is crowded.
* Introducing mice too quickly can cause stress and injury.
If you are thinking about getting a second mouse, it's crucial to do your research and consult with a veterinarian or experienced breeder to ensure you can provide a safe and comfortable environment for both animals.