Mice Pregnency

Question
My mouse looks bigger than she did when i got her which was a week ago, shes been spending a lot of time building a nest in her little wooden house and shes been also spending a lot of time on her wheel, does that mean anything? & If shes pregnant do I need to give any care to the baby's or can she do it on her own?

Answer
Hello Star,

Most pet shop mice are sold before they are full grown, so she may just be growing up! Rearranging her home may not mean very much in this context since she is still getting used to her new environment, and running on her wheel is a great sign that she is healthy and happy.  If her growth has all been in her waist section, especially if it becomes definitely rounded, I would start to wonder if perhaps the shop had a sneaky boy in the girl cage.  Pregnancy lasts three weeks in mice, so you only have two more weeks to wait until you can safely assume it was just growing rounder. Unfortunately, there is no way to tell for sure outside of waiting and seeing.

If she is pregnant, all you have to do for her is make sure she has a clean cage, plenty of food and water, and an escape proof cage. You can give her little strips of tissue or toilet paper to rip up and nest with if you'd like.  For babies, mom does all the work for you unless something goes wrong. You may want to leave them alone for the first week, since she is new and may be stressed or anxious, but after that they will start to explore and try out foods at their own personal pace. Speak to the pet store you bought them from and see if they will take the babies once they are old enough (four weeks or as soon as you spot them trying their water bottle - be sure to separate boys from girls!).  They are really pretty easy!

If you have any other questions or need more details just let me know and I'll be happy to help!  Congratulations on your new pet, by the way! :)
-Tam