rescued rat not sure if shes pregnant.

Question
Hello i ased a question a few weeks ago about my rat having no vagina well she still does not have one but not to worry lol.
As the rat is unable to breed i decided to get a new one but i got a phone call from a friend who know someone needing a hame for 3 female rats aged about 5 months so i said yes as it was possible for them to become snake food.Any way i got them last monday and there very sweet but marmite a black/white rat did look a little round but not much so i took no notice as they had not been fed for two days so i put it as bloat from myself giving them a good diet.The last couple of days she has a larger belly and its only around the stomack she not fat any where else could it be possible she is pregnant from what i have told you.?I know its best to take a female out when near birth and im being prepared just incase i just have no way of knowing if the previous owners if you can call them owners put her with a male what do you think i should do.?

Answer
My recommendation is to keep a very close eye on her. Make sure you have a separate home set up for her, and since rats do not tend to really show their pregnancy until the last week, I would separate her from the others now. A good way to tell if she is pregnant is to look at the other girls bellies, their nipples are noticeable but they are fur covered and not protruding. Then look at her belly, if her nipples seen to stick out, and have hair missing all around them- this is a sign that her body is getting ready to feed a litter of babies.

A good cage for birthing is a tank or cage with extremely small bar spacing (so that no babies fall out of the cage). Give her a shoe box, or soda box, or something of that sort to have her babies in. Rats like to hide and have privacy when birthing their litter... My favorite thing to use for mommas and their babies is a box from a 24 case of Dr. Pepper because it has this new design and it's PERFECT for them. I cut out a little opening/doorway where there was already a small opening to get the cans from, I just make it larger. Be sure to leave a ledge that is atleast 2 inches tall at the bottom, a lip. Give her something to nest with such as paper towels with no ink on them, fleece scraps, wash clothes ect.. Whatever she nests with should be free of strings as these could tangle around a baby... Do not use toilet paper or carefresh bedding during the birth, carefresh will stick to the babies like glue and could rip the skin or get caught around the nose of the baby and suffocate it, toilet paper is also a suffocation hazard.

It's important to leave momma alone when she is birthing the babies. It might be exciting but if she's untrusting of people even a bit, and gets nervous, the babies could die as a result..

Usually, on the day of the birth if you can hold her against your chest you should be able to gently place your hand on her belly and feel the babies moving around, sometimes you can even see them!

Now, if she continues to grow larger in the middle and no babies emerge, you could never see them moving, never felt them moving, and no other signs of pregnancy, this could be late onset megacolon. Signs of megacolon are:
-bloating
-failure to thrive/large mid section but extremely skinny everywhere else.
-extremely foul smelling Diarrhea
-delayed passage of stools, or sometimes none at all.
-impacted fecal matter in the colon that is visible.

Megacolon is a serious disease and is not curable. Sometimes (very rarely) it can be managed but it takes a LOT of work and patience. If megacolon is the case, euthanasia is the most humane choice.