How to Tell If Your Rat Is Pregnant

So maybe your rat escaped and went canoodling in the bucks’ cage, or maybe you picked a suspiciously round female out from a feeder tank, or perhaps you’re breeding rats intentionally (if so, I hope you’re a reputable, responsible breeder)– either way, you need to know if she’s pregnant! Since rat gestation is only 21 days, it’s important to know when your doe is pregnant and when she’s due to deliver. The last thing you want is a surprise litter in  a cage full of other females, who might steal the babies and prevent them from nursing!

Weight Gain

If there is any chance you may have a pregnant rat, you need a gram scale. A decent one can be had for $10-$15 at any grocery store or big box outlet, usually in the baking section. Set a large carton on the scale, zero it out, then set the rat in the carton. Wait until the numbers stop fluctuating, then write down the number the scale settles on.

When trying to determine pregnancy, make sure to weigh your rat at the same time of day every day, as exactly as possible. I usually weigh at 10 PM. Rats’ weight will change hour by hour, so the time of day is very important. I have some rats who have as much as a 10 gram difference in their weight from the morning to the evening each day.

A good rule of thumb is that if a female rat gains half an ounce (a little over 14 grams) in the first three days after mating, she is pregnant. However, some rats may gain only a couple of grams each day until the second week of pregnancy. If your female rat gains weight steadily, with the daily gain increasing over time, she is likely pregnant. In the third and final week of pregnancy, weight gain will be very rapid.

Other Signs

You must, must, must weigh any rat suspected to be pregnant, in grams, daily. However, other signs will be present and can corroborate the conclusions drawn from weight gain, or lack thereof.

Most obviously, a pregnant rat will appear to have a rounded belly  and protruding nipples as delivery draws near. You may also note some behavioral changes, such as increased food hoarding or nesting behavior. Reduced activity is normal in the second and third week of pregnancy, but complete lethargy is not. Some pregnant does may become very friendly, while others become shy and avoid handling.

When a pregnant rat is about to deliver her litter, she will build a noticeable nest and may not come out even to eat or drink. Some blood spotting on the bedding may occur when labor begins. If it continues for more than a couple of hours and no babies appear, your rat may need to see an emergency vet. However, the majority of pregnant rats deliver easily without human intervention.

If you have a round female rat with a large nest about 21 days after her last exposure to a male, the best thing to do is leave her alone, turn out the lights, and listen for squeaks! Trust me, if live babies are delivered, you will know. They are not quiet!

Related Posts Plugin for WordPress, Blogger...
Please follow and like us:
Visit Us
Follow Me
Follow by Email

25 Responses

  1. jermiah
    | Reply

    I have had my female feeder rat for about a month now . T have been breeding them but, i cant tell if shes pregnant

  2. Autumn
    | Reply

    I’ve got two rats from Petco and one of them has been acting a lot like that described here and it concerns me. She’s been fighting with the other rat I purchased a lot in the last week, she looks bigger [and she was big for a “medium”, as Petco called her, sized rat anyway.] She eats and drags food off into her corner, if the other rat comes near her it results in a mild fight most of the time, and she usually lounges around. The first week I had her she wasn’t exactly out going, but she was much more comfortable in her new setting than she is now. Now, she just lays either in her hammock or on her little hutch a lot. If she’s pregnant, she’s pretty far into it at this point. We’ll have to wait and see…..

    • ROBERT
      | Reply

      my rat is doing the same thing

  3. Courtney
    | Reply

    I had just recently bought my two rex-sphynx mixes. One male (Snickers) and one female (skittles). I had bought Skittles first, then bought one of the males she was enclosed with at the pet store. I bought her around 6-7 days ago, Ive read up on the female rat. Ive read multiple websites, some say females go into heat evry five days, others say its once a month for a 3 day period. Do you know of how long and how many times a female rat is in heat for? And i just took her out and looked at her, She has a small bulge in her stomach, closer towards the pelvic area, and her nipples are bright pink. Does that tell me anything? Like is that a sign of pregnancy?
    Thank you,

    If you have any answers or references for me to view please email me,

    thanks again.

  4. girly girl
    | Reply

    that is a great question but i also have a question do rats breed at night or any day of the week when they go into heat

    • kylie
      | Reply

      Some rats will mate anytime, anywhere, without any concern for what is going on around them. Others need a suitable area/environment to breed successfully. Often a one story cage or an aquarium is used. This gives the pair a larger flat area to mate in. And if your male is older, or your female is very active this will make her more accessible to mounting (and keep him from having to chase her all over the cage). Use appropriate cage bedding for the bottom making sure not to use too much, during mating it is not uncommon for the rats to kick out a lot of bedding.
      If you are just leaving them in overnight you will probably not need anything more than a food dish and a water bottle for them. A soft towel added to the cage will give them a resting spot. If they are staying together longer a larger cage may be appropriate and a house and/or a hammock will make their environment more comfortable. Keep in mind to leave an open flat area for him to mount her. this website will tell you more thanks kylie hope it helped

  5. girly girl
    | Reply

    i am starting to breed rats because i am tired of buying rats for my 3 foot ball python to eat every week so i am trying to breed her to the male i just got 2 days ago but i don’t know when or how they are going to do it though so i need some edvice from some experts instead of a petstore personale. thank you very much and have a great day

    • Rat lover
      | Reply

      This is a site for “pet lovers” not “pet killers.”

      • Animal Lover
        | Reply

        Sorry to inform you, but snakes aren’t vegetarian. They eat rats. Get over it.

        Someone who ownes both rats, and animals that eat rats.

  6. rat girl
    | Reply

    My friends has to rats we dont know what they are..But one is albino and she is much bigger and more round and eatting alot of snacks and food..We dont know what to do

  7. rat lover
    | Reply

    hi. i bought 2 female rats like 2 weeks ago and now i am terrified because they are getting very round and hide in their hammock and hutch a lot please help me because im terrified that they are pregnant
    and if they are im not prepared to deal with all the deaths. they are only 6 weeks old…… please help…..

    • kylie
      | Reply

      when you got them where they in the same cage as the males if so they might be pregnant they can breed from 4 weeks old the younger the rats are the smaller they will turn out full grown if you want big rats wait until fully grown then breed

  8. breann
    | Reply

    I got my rats cheep and i dont know if one was a boy or a girl, and i think one is pregnate because they got all of the rats at the same time and you can tell that one is bigger but i dont know if its muscle or if it is pregnate, also it doesent eat as much as the smaller one does, but it drinks water 24/7.

  9. Anna
    | Reply

    @girly girl

    Rats do NOT go into heat.

    • luh
      | Reply

      Yeah they do, every 4 days. It’s not a bleeding heat like with dogs and it lasts for an evening, but you will notice that they become more active, arch their backs when you touch their rumps and their ears may wiggle rapidly (apparently it’s “sexy” for the boys, lol)

    • Tyler Jones
      | Reply

      Rats go into heat every 5 hours, and when they do, they will arch their backs and expose their hind quaters… This usually means your rat is a whore if there are no males with her. My Taffy is no whore, but she did get knocked up before i bought her… I’m proud to be having a litter of fuzzies, but don’t ever breed just to feed a snake. That is just disgusting and you should be jailed for animal cruelty.

      • none ya
        | Reply

        how it it cruel, it’s why most rats are born.
        i wouldnt do it, because i love my babies but if they have no emotional attachment i say do it

  10. ashhy girl
    | Reply

    i breed rats al the time for pet shops and i have had about 100 babies and its not that hard to breed them or tel if there pregnant but one time i did put my guiea pig with the female rats and i think he mad one of them preg so i dont kno what there going to look like.

  11. Tyler Jones
    | Reply

    Most of the people posting here are just sick… I got my rat Taffy when she was 5-6 weeks old and have had her for about 3-4 weeks. She is getting very round, and discharging a clear vaginal fluid(Means she is pregnant). When i read of people afraid of their ratties being pregnant it just makes me mad because when you get a female rat from a petstore(which most of them are not taken care of properly) then expect her to be pregnant. I was told that they were 99.5% sure that she couldn’t be pregnant, and here i am getting ready to have a litter of fuzzies. It pisses me off when you kids say you started breeding just to feed your snakes… That is just sick… Don’t ever start breeding if you don’t know anything about ratties because that is just disgusting of you. Get some mental help and don’t be lazy, if you get a snake feed it regularly, but don’t start breeding just to feed it.

    • B Connor
      | Reply

      Where do you suppose snake food comes from? I would be willing to bet that it comes from somebody breeding rats for soul purpose of food. As they say if the rat ain’t squeekin the snake ain’t eatin’.

  12. Julianne
    | Reply

    I recently took in two rescues from a girl who can no longer care for them. I added them in with my other two girls (one who had an accidental litter in August from getting into the boys cage during roaming time.) I am absolutely in love with them but I am noticing that both of the rats nipples are exposed and their stomachs are getting rounder. On top of that, they are beginning to make nests. I am unsure if they are just gaining weight because of their new diet or if the previous owner handed them over because she knew that they had a male encounter and are now pregnant. Guess we will find out soon enough! Oh boy, baby ratties!

  13. ROBERT
    | Reply

    i got my round christmas time made she realy fat she fight with the other famale rat i cant tell if pregnat or what

  14. ashley
    | Reply

    I am in love with rats I breed for pets only I feel people should feed snakes the ones already dead or frozen

  15. Riv raster
    | Reply

    My female (bonnie )rat is not letting me pick her up and she is fighting with my male (Clyde ) she drinks very much but not eating as much as usual and she is getting fat.


Leave a Reply

Your email address will not be published. Required fields are marked *