So we have a breeder mouse that has basically become a pet mouse now that we arent breeding them anymore. Well about 3 weeks ago we put her in a recently vacated hamster cage(long story there). And within 2 days we found that here was a wild brown mouse visiting her. We arent sure how it got in or why she didnt get out but it has since been picked off like the hamster that got out and every other rodent in the yard by our two pitbulls. But today we are looking at our pet mouse and she sure is getting round around the middle, so like I said mousy love...