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Mice/Feeder mice vs fancy mice


QUESTION: So I recently had a gift exchange and some of my friends decided it would be funny to get two mice for their gift. I took them because i have had pet rats before and two mice is not a huge commitment for me. However, they thought it would be funny to purposely buy a male and a female. The mice were in a cage together for almost two days. How likely is it that the female is pregnant? I'm not sure how old they are, they're pretty tiny. I have them separated now, each with a roommate of the same sex. I will be able to handle the babies, i just want to be prepared.

ANSWER: Dear Ellen,

Without making explicit how I feel about someone who would think playing with animal lives is "funny"..... I am very glad you were there to be sensible and love the little mice.

If they are super small you have a good chance. Is the little boy pretty obviously a boy? If he still doesn't have much in the way of testicles, you might be OK.

Another thing you may have on your side is that mice "only" go into heat every 3-5 days. If you got lucky, she wasn't receptive to him during those two days. Of course that is irrelevant if they came from the same cage at the pet store.

One thing to do is ask, if you are still speaking to these friends, if there was a lot of squeaking and chasing in the cage.

However, other than these circumstances, well, male mice do take advantage of the situation pretty quickly quickly when they have contact with a female.

I have another bit of unfortunate news for you:  in your extreme kindness in making sure they wouldn't be lonely, you were not aware that male mice, completely unlike male rats, usually must live alone. Two male mice, other than family members who have never been separated, often fight- and they will fight to the death. You may end up with even cage number three.

If you do end up with babies, although I have not had rat babies I believe from talking to breeders that the two species are similar. The main difference that I am aware of is that rats are not as crazy when they open their eyes. Mice can pretty much go nuts when they open their eyes, and those little critters in this "flea stage" or "popcorn phase" can jump up to two feet up in the air. They are easy to lose, even when they have been well socialized.  

Again, thank you for taking in these little unfortunate tykes- they could, without you there, could have had a pretty unfortunate experience, since many people think it is perfectly fine to let fancy mice go in the wild. Of course they would not last more than a couple of days, even in the summer.

Enjoy them!


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

QUESTION: I forgot to mention that these mice are feeder mice not fancy mice. Does that change anything? Also, the two boys seem to be getting along pretty well, they cuddle a lot. If they were from the same pet store is there a better chance that they will get along?

Dear Ellen,

The only difference between feeder mice and fancy mice is how they are bred. Some places just breed them all the same-- so a mouse could be sold as either. Other places breed separately, and so the difference is that the feeders are not bred for health, temperament, or longevity. They are still mice, and mice are always wonderful. Let's hope they came from good stock.

You might get lucky with the males. Or they may start to fight later.




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I can answer questions about raising mice and caring for them as pets, with knowledge from my 38 years of having fancy mice as pets. I have NO MEDICAL TRAINING and you should take a sick mouse to the vet; but if you simply can't, I will try to help you. I LOVE PHOTOS!!! I ALSO LOVE UPDATES! Let me know how the little tyke is doing later on, for better or worse, especially orphans. It also helps me to help the next person. Please first search first: use 'Natasha Mice Mouse' with whatever else your question includes. Or check out these links: **** YOUR FIRST MOUSE (my video; rough draft): **** TEN VIDEOS ON RAISING ORPHANS: **** SEXING MICE: **** And some GREAT MOUSE INFO SITES:


I have had mice for 40 years (since I was 5!). I raised them when I was a child but now I keep all females, and never fewer than three so that if one dies the others are not devastated, because they have each other.

I run Rats and Mice are Awesome on Facebook. The official name is Rats are Awesome.

B.A., M.A., M.A. in Linguistics: Yale University and University of Connecticut

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