You are here:

Mice/Folow up question


QUESTION: I had a lone female mouse, and I wanted to get her a companion.
I went to our local petstore and got two supposedly female mice.

After a few days, I noticed that one seemed to be male.
we took the mouse to an expert who verified that he was male.

Then I had two females, one around a year old, and the other one probobly
3-5 months, along with the male.

Then I noticed that the few month old mouse seemed to be pregnant,
and I looked up what pregnant mice look like and I think I am right that she is!

On a website called The Fun Mouse, I found an article on breeding.

It talked about all the things that can go wrong, the mother can kill her babies,
it would be terrible!

I am only 11 years old and I don't think I can handle that much pain and drama!

I don't know what to do, even reading the article made me really upset.

How do you think I can handle this?
Is there any safe, natural way to stop her pregnancy?

If I can't stop it without hurting her, how can I make It more likely
that everything will be OK?

Please help!

ANSWER: Hi Miriam,

First, calm down, it's going to be okay!  :)  The very first thing to do if you haven't already is to separate the boy mouse from all other females.  Boy mice should always be kept by themselves and don't need friends besides you to keep them happy.  Girl mice, on the other hand, do in fact do best with friends, but if she isn't too close to having her babies it may be best to move the potential momma mouse to her own enclosure (glass or plastic tanks with plenty of air flow are better than ones with bars, so that babies don't escape when they start to explore) to reduce her stress.

There is no way to safely stop her pregnancy.  If she is in fact pregnant, and you do not want her to have the babies with you, could the expert you went to see possibly be willing to help you out?

Let's talk about mouse pregnancy for a second, because I don't want you to be scared about it.  Can things go wrong?  Absolutely.  Are they likely to?  No!  Like any other animal, a momma mouse wants to know her babies are going to be safe.  We accomplish this by leaving her alone if she seems stressed (hiding a lot, running from you, squeaking) and not peeking in on the babies until they start to come out on their own.  We make sure she has lots of food and water at all times, and that we don't disturb her nest until the pups are at least two weeks old.  This might mean not cleaning it for a little while, or only cleaning half the cage if she lets you (I like to pull a handful or two of dirty bedding out from the other side of the cage and put some more in, easy peasy), but don't worry - mommas keep the nest area very clean all on their own.

It can be hard to verify if a mouse is pregnant or just gaining weight.  The best and surest way to tell is to wait!  From conception to birth, pregnancy for mice takes about 21 days (3 weeks).  Sometimes it takes a couple of days less or more, but if it's been 4 weeks since you separated them and there are no babies, then it's safe to say no little ones are on the way!

What do momma mice need?  Momma mice need protein.  It's a good idea to take a few pieces of cat kibble and mix it in with her normal food, like treats.  This will help her stay healthy as she focuses on making baby mice.  Mommas need water - never let her water get low and always tap on the bottle sipper to make sure water is flowing when you replace it.  Mommas need a clean cage, especially since you might not be able to clean it once pups arrive!  If she has already built a nest, it is okay to clean everywhere else in the cage except the nest.  You may not see the pups when they arrive, so leaving her hide alone is the best way to avoid accidentally exposing them.  Momma mice need to stay calm and happy.  If she becomes nervous when you are around, give her some space - for instance, if she is in a high traffic area of your home, consider moving her somewhere calmer.  Some mice are very affectionate - if she still wants to cuddle you and see what you are up to, don't worry about moving her.  It just depends on how she behaves.  A mouse that runs frantically, stares, rushes to her hide when you are near, may need a calmer spot in your home.

What do BABY mice need?  When/if she has her babies, she will do all of the work.  The only thing you need to do is make sure she has food and water and that her cage does not start to smell.  Around 10-14 days the babies will grow in their full coats and open their eyes (sort of, it's different for every litter, so if they don't open their eyes at the same time don't panic).  It's also around this 2 week point that they will start to explore from their nest, try to gnaw on solid food, and play with each other.  They will continue to nurse until around 4 weeks.  Once they learn how to drink on their own from a water bottle, around 4-6 weeks, the boys will need to be separated from momma and the rest of the litter to prevent more pregnancies.  The mouse expert should be able to help you determine their genders, or you can write me back and I'd be happy to help.  Brothers can live alone but will need watched very carefully, because as they mature they have a higher chance at starting to fight, and if they do fight they can fight to the death.  If you are keeping the babies you will need more cages, if not, it would be best to adopt out boy mice individually instead of in pairs.

So let's talk now about this killing-the-babies business.  This does not happen as often as people think it does, although it is a possibility.  There are three possible reasons a momma will kill her babies.  First, some mommas can sense when there is something wrong with a baby and will kill it because it will not survive anyways.  It's very sad to see, but on rare occasions, it can happen.  Second, some mommas have no idea how to be mommas, and don't understand what all these wiggly pink things are that came out of her!  This is also quite rare, but if that happens, it usually only happens on her first litter and in young mice.  The last and most common reason for killing the babies is if she feels they are in danger.  This is nature's way of preserving her nutrients so that she can have more babies in the future.  The key to preventing this is to make her environment feel as safe and calm as possible.  This is why I suggest removing her from the other females and taking the male out of the cage as soon as possible.  Now, in years of breeding mice, I have only had this happen twice.  Twice!  It's heartbreaking, but it does not happen very often at all, okay?  I can't tell you there isn't a chance, but I can tell you how to minimize the chances.  I want to suggest again that if you think this is going to be too hard for you, talk to your parents or guardians about finding a responsible, experienced mouse owner to help you.  Maybe they can babysit her until the babies grow up and she can come home again?

I understand why you are scared, but you have to understand that this information is there so you are prepared for the WORST CASE situation.  Not all momma mice kill their babies.  Most babies grow up happy and adorable!

I hope I've helped, and please let me know if you have any other questions, okay?  Last but not least - congratulations on your possible baby mice!  :)


---------- FOLLOW-UP ----------

QUESTION: Hi, thank you for the answer.
We have had a LOT of things happening with the mice.

First of all, the two littler mice actually ran away the other day!

I never saw Mowta, the male, after that.
But the supposedly pregnant mouse stayed under a tree stump in the backyard all night, and this morning I was able to bring her home again.

I miss Mowta, but freedom was probably the best thing for him.

Anyway, my question now was,
Sky, the mouse who is pregnant, must have gotten very scared and stressed out there alone, and you say stress is usually what makes something go wrong.

Now she is back safe in her warm cage with her older female friend,

and she seems healthy and active,

but do you think being outside in the cold all night before I could catch her too much?

What do you suggest I do to help her calm down and feel safe enough?

It probably was very stressful, but now that she is inside, warm, and with a friend she should be just fine.  I worry sometimes about female friends in the cage because it means BOTH mice have to be good mommas, but if they do well together, hopefully it will be fine.  I typically separate a pregnant female (even if she can still see the other mice) early in the pregnancy so she has some time to adjust to being alone and won't have to worry about protecting her babies from other mice.  Which way you will want to do it just depends on how happy she seems and how well they work together.  If she is due any second now, it would be easier on her to leave her with her friend.  You will want to put them in an escape-proof cage, though, because remember, baby mice can become very adventurous when they start to explore!

To help her calm down, do just what you are doing now!  Give her a little space, some comforts like a safe hide and plenty of food and water, and you can even tear up tissues to give her a bit of nesting material.  Just be sure not to use cotton balls, as the tiny threads can be dangerous to babies.

You're doing a great job.  Remember that if you ever feel like you cannot handle it, you can ask experts in your area to give you hands-on help.

Keep me updated!  :)


All Answers

Answers by Expert:

Ask Experts




I can answer questions regarding mice as pets, mouse behavior, color and coat genetics, breeding techniques, and general health questions. I can help with caging and setup, nutrition, social issues, and what to do in most mouse emergencies (such as unplanned litters, injuries, fighting, etc.). I can also assist with questions pertaining to orphaned mouse pups, weaning litters, and questions of mating and birthing. I cannot answer questions about exotic or wild varieties of mice such as spiny or pygmy mice. *****FOR EMERGENCIES, anything requiring immediate medical intervention, PLEASE take your mouse to a professional veterinarian or wildlife rehabilitator who works with mice as soon as possible! IMPORTANT RESOURCES: Raising Orphaned Mice: Orphaned Mice Videos: Natasha's Your First Mouse: General Mouse Help: Mouse Info and Exotic Breeds:


I have enjoyed the companionship of mice nonstop since 2004, and spent a year caring for them in a lab where I learned a great deal about their breeding, social needs, and health. I spent a few years breeding them, specifically working with albinos, marked mice, angora mice, and satins. My education never stopped - I am learning something new every day from current and well-established research thanks to the wonderful folks at the Jackson Laboratory, as well as from my wonderful mousey friends online. I also love learning from my terrific questioners here on AllExperts - you folks keep my passion for these amazing animals alive and well!

East Coast Mouse Association - expired, American Fancy Rat and Mouse Association - expired

Partial University for a B.S. in Microbiology, Partial University for a 2-year degree in Veterinary Technology (RVT cert), C.E. classes in pathogens, aseptic technique, genetics, and applications

©2017 All rights reserved.