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My male mouse is gaining weight. Did I get a female? Separate them?

Updated On September 23rd, 2025

Pet's info: Other | Unknown - Other

I purchased two mice, however, one had to be returned because he was being aggressive and attacking my other male mouse, so we traded him out with another male mouse, however I'm not sure if the new little "guy" was sexed correctly... as patches the new mouse has been gaining weight and has become a bit skittish... I think maybe we got a female as a mistake, what should I do? Do I need to separate them? Or are they okay to stay together? Peaches is a male with visual indicators easily spotted.

1 Answer

Most Helpful Answer

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Answered By Dr. Elizabeth

Veterinarian

Published on October 24th, 2017

I would recommend for you to take both mice into the store where they were purchased and ask someone to look at both mice to tell you if you got a female by mistake. Mice reproduce VERY quickly so you need to know this asap. If you infect have a female, the pet store may offer to take the babies. I would also recommend to keep males separate from females and to have pairs of mice so they keep each other company. Best of Luck with Patches!

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