Reptile & Amphibian Forums

I have been reading through the forums looking for the answer to this question and have not found it so I thought I would ask.
I have started a colony of both rats and mice. They are both colonies of 1 male to 3 females, the room temperature is between 70 - 80 degrees and they are housed in aquariums, 55gal for the rats and 30 gal for the mice.
Now my question is this, how do I tell if my animals are pregnant?? I have not witnessed any breeding in the rats at all. When I bought them I was told that 2 of the female rats may be pregnant already, but I do not know how to tell for sure.
The mice showed some sporadic breeding activity in the first few days but for the last 5-7 days I have not seen anymore activity from them.
Thank you in advance for your help.

>>I have been reading through the forums looking for the answer to this question and have not found it so I thought I would ask.
>>I have started a colony of both rats and mice. They are both colonies of 1 male to 3 females, the room temperature is between 70 - 80 degrees and they are housed in aquariums, 55gal for the rats and 30 gal for the mice.
>>Now my question is this, how do I tell if my animals are pregnant?? I have not witnessed any breeding in the rats at all. When I bought them I was told that 2 of the female rats may be pregnant already, but I do not know how to tell for sure.
>>The mice showed some sporadic breeding activity in the first few days but for the last 5-7 days I have not seen anymore activity from them.
>>Thank you in advance for your help.
>>
I can't tell how long you have had them all set up but since gestation is 3 weeks and often when you set up a group they either reabsorb or abort if the male is not the dad. That said too they take time to settle in to breeding. Often if they are 'older' they take longer than if they are young and need to grow some. I would guess you have a week or two to go.
The way to tell is ONE if they look like they are big enough that they will explode you are close. or TWO you put them together and 'plan' a mating with a pair you have paired before and know they take easily. That is with rats. With mice I set them up and don't bug the 'dynamics' Mice are too flaky.
With some, especially rats they may not look heavy at all but drop 15 pups just like they should.
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Sonya

will give birth in about 21 days from when they were impregnated, unless theres something wrong with your male. good luck. dave

There really isn't a way that i've found to tell right away. A few thing I look for, are the male doesn't show any breeding interest. you will see the momas sides looking fater about a week or so before, and if it is the first litter the nipple hair will fall out. Hope that I help give you some idea.