Breeding Mice

Question
QUESTION: Ok, I figured out who is going to go with who. But now my question is, right now I have the girls in one 20 gallon tank the boys in another one, I have 2 pieces of plexi to divide the tanks from when they were used to house snakes, the plexi has holes for ventilation would the males try to fight through that and also I have read that if a female smells another male she may reabsorb her litter, are these things I am going to need to worry about?

ANSWER: Hi Randy,

I'm glad you figured out who to pair!  :)

Yes, unless they're really laid back, they're probably going to fight through the air holes.  I have a pair of bucks whose cages I placed too close to one another once - long story short, each has a shorter tail now.  You would likely get injuries while they were trying to climb up the holes.  They'll also probably chew those holes outward, since mice can chew through almost everything except metal and glass, which would lead to one escaping into the other's territory and causing problems.

The easiest fix would be to pick up some thick wire mesh (thicker than screen door, but with at least a 1/4 inch hole or smaller - you can usually find this at the hardware store in the gardening department for a few bucks).  You can then glue one or two sheets over each side of the dividers.  This will add a little space over each hole so that no one can chew it wider or reach all the way through the holes.  Total cost would be about $5, if that, you wouldn't have to buy new dividers.

Of course, being so near to other males will still stress them out, so if you notice they're not acting right, paying far too much attention to the other boys, or otherwise not being as laid back or happy as they could be, you might want to look into finding a more divided setup.  If you're going to be breeding as a habit, it's worth it to look into making cages out of buckets or R-U-B's:  http://www.fancymicebreeders.com/woodlandmousery/9l-rub.htm  (I did not write the guide)

Making your own cages can save a bunch and allow you to customize them, but does take a little craftiness.  There are several ways to do it, too.  If you're planning on having several litters and keeping most of them, or a number of bucks, it'll be worth it in the long run.

As for smelling other males - I have never heard anything about smelling other males leading to the litter being reabsorbed, though that only proves I don't know about it.  It shouldn't come up, though, especially if you cycle the males through the female cage instead of vice versa.  The smell is in the bedding and anything he urinates on (and him, of course), so by putting him in her cage and no other male at that point, she'll only be able to smell his hormones.  Then, by pulling him out of her cage before she is due and giving the cage one good last change before the pups come around, you remove most of his smell, resulting in a momma that's a little less stressed out (because I'm sure you've noticed - female mice are usually somewhat harassed by the males!  Stress = higher risk of complications or anxious behaviors).  It's nothing that would freak her out by simply being in the same room as multiple males, though if you're concerned, it certainly wouldn't hurt anything to keep them in separate areas.

-Tam

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

QUESTION: Thanks, but since I have all 3 males in the same tank, when they get put in with the females that might cause them to become territorial? even though right now they are all getting along fine. I was also wondering if it was normal for the males to be getting along better than females, because the females all bicker over the same piece of food while the males will each take their own block and if one of the others comes over they will drop that one and go get another one

ANSWER: I'm not sure if I misunderstood you or not - you were asking if the males would fight through the holes in the plexi glass, right?  I had assumed they were all separated by the partitions now.  Males are, like you said, more likely to fight with other males if any of them have been sexually active in the past (though they are not aggressive with the females).  However, the problem is that although some males appear to be getting along well at first, when they decide they don't like each other anymore it can be very sudden and lethal.  For this reason I highly advocate keeping all males who were not born together, or who have been sexually active, physically separated from other males from the get-go.  If you are breeding as a hobby, this is something you'll run into fairly quickly, and I don't want you to lose any of your bucks.

How females behave around other females is not uniform, just like it isn't the same for all males.  Some females are nice to other mice, some are territorial, some are great moms, some are poor moms, some like to chase and steal food, and some are very submissive.  It just depends on your mice and the social order they set up.  By observing them for a few weeks you will be able to get an idea of everyone's temperaments and who has become the top mouse in the cage, which will also help you establish from whom you would prefer to breed (since temperament is frequently affected by genetic factors).

Hope I answered your question,
-Tam

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

QUESTION: No you were correct I was asking if they would fight through the holes of the plexi, I don't have them divided yet because I only have the 2 aquariums and even the oldest female is not 3 months old yet, so I did not want to put them together yet. Also the breeder had the moms together and so they were all raised in the same cage and have lived together all their lives with each other and since I have had them for just over a month they have never even squabbled that I know of and I am up all night when they are out and about. But all of the mice are really gentle towards me and will climb up on my hand, but when I go to pull my hand out of the tank they jump off, no matter how slow I do, I know they are not gonna get hurt because I remove all hard objects except for the nest box when I am going to try and pull them out, I leave only the empty paper towel rolls and in the aquarium I have 4-6 inches of bedding for them to burrow through, but I would like to be able to pull them out without having to hold the tail while I do it because it makes cleaning the tanks harder for me as well as when I go to put them from the little carriers back into their main home, any ideas?  

Answer
Okay, I'm glad I understood you correctly then.  :)  They may just be arguing a bit more because of the change - any time something big changes, like going to a new home, they can behave a little differently for a while.

If they insist on jumping off your hand, no matter what speed you move it, you can try lifting them out while they're in hides or paper towel rolls.  This will allow you to quickly move them from one place to another when you need to clean.  Definitely keep trying with your hands, though - they may just need a little more time to get used to the idea.  When you're playing with them outside of cage cleaning you should definitely continue to handle them and show them that being lifted doesn't have to be a scary thing.  Pumpkin seeds and yogurt treats are always helpful!

-Tam