Pet mice

Question
I was wondering how to tell if the mouse is male or female. I know with rat's you can totally tell if the rat is a male but with mice it seems to be different. We just got 2 mice. Family pet's and I want to make sure what they are just in case. Thank you so much for taking the time to answer my question.
Debi

Answer
Hi!

If the mice are old enough, it should be no trouble at all! The male's testicles are very clearly visible when he's relaxed. This can, however, be difficult to see if the mouse happens to have long fur. The most certain way to tell is by checking the mouse's belly - you should be able to see the mammary glands if it's a she and if there aren't any, it's a he. Hope this helps, and best of luck to the new family members!