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Mice/is my mouse pregnant


I have two mice male and female and i wanted to breed them so they share a cage. Bubbles the female used to be nice. She wasnt hand trained yet but she didnt mind being held if i picked her up. Well after whiskey and her had some time together her mood began to change. I can no longer put my hand in the cage nor pet her. She rattles her tail and bites me. She sleeps more now and whiskey seems more protective. Bubbles is always alert when shes awake and whiskey stays by her side even when he gets attacked. They squeak a lot at night but that seems normal. Also they have been digging all of the bedding out of the corners of the cage and barricading their house. Are they ok? Should i be concerned or is this normal?

Hi Alauna,

Whiskey needs to be removed immediately.  It sounds like Bubbles may have babies on the way and is beginning to nest.  There are many reasons why it is dangerous to keep the male in with the female past the initial 1-2 weeks of breeding:

-Male mice may see the pups as competition and eat the babies

-Stress from continuously being pursued by the male (the squeaking you are hearing at night) may cause the female to eat the babies out of fear for safety

-Bubbles will ovulate again the same night she has her babies, meaning she can (and usually WILL if the male is present) become pregnant immediately after giving birth.  This does not give her body a chance to recover and can harm or even kill her, as well as leading to a litter being born before the first litter of babies is old enough to stop drinking milk.  Older babies can trample younger babies to death.  PLEASE do not allow her to have back to back litters.  Please remove Whiskey as soon as you read this and give him his own cage.

Mice take three weeks from the night of conception to have their babies.  That means you can expect little ones anywhere from three weeks past the date of putting them together, until three weeks past the date of separating them.  If one month has gone by since removing Whiskey and you have not seen or heard any tiny peeps, it is safe to try again.  I recommend keeping males and females who are being bred together for 2 weeks at maximum.  This gives plenty of opportunities to breed and removes the male in time for the female to begin nesting and settling in for the birth.

Stress is very bad for new mommas.  Since she is scared by your advances, let her be until her pups are old enough to fend for themselves (a few weeks old).  Only open the cage to remove Whiskey, to spot clean the bedding (remove a pile of too-soiled bedding from the opposite side of the cage from the nest and replace with fresh bedding - you do NOT need to clean the nest), or to add food or water.  Don't bother her any more than is necessary, and keep everything in her environment as regular and calm as possible.

During the first week of life, the pups will stay in the nest she has built and she will come out to guard them or get food and water.  She will keep their nest and the babies clean, well fed, and warm all by herself.  Once mouse pups begin crawling out to explore the cage you can slowly begin to reintroduce yourself to her and her new babies.  Always stop when she becomes agitated, and never lift a baby mouse when she can see you, ever.  Momma mice are very protective and great parents!  Around 4-5 weeks of age they will be eating and drinking from the water bottle, and once you are sure they are getting their own hydration, you can separate the boys from the girls.  Be careful - male mice will NOT be able to live with their father, and ideally should be kept in their own cages (one male mouse per cage, 2-3 female mice per cage, no mixing of genders).  This is when you can start finding them responsible homes...unless you are ready to have a lot of mouse cages!  :)

If you have any questions please let me know, and congratulations on your hopefully upcoming new litter!



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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

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