Pet rat acting funny

Question
QUESTION: Hi, we have had our female rat for 20 days. (The pet shop said she was about 5-6 weeks old when we got her). My son is trying to train her to climb a pole for a school project.  She climbed right up it the first time he showed it to her, and now she won't have anything to do with it! WE have spent time bonding with her outside the cage and she has been marvelous.  Today when I tried to get her out of the cage, she bit me! It was more than a nip, it was a bite on my index finger.  She is acting very funny.  We did finally get her out and she hid in my son's sweatshirt sleeve the entire time.  She seemed very "nervous" and not herself.  She is growing and getting bigger, is there any way she might be pregnant? She was in a mixed tank at the pet shop.  She was also sneezing.  She has been nesting and hoarding food in her little house.  If she was pregnant, wouldn't she have had the babies by now?  We got her for this project, but we want to keep her as a pet.  Any ideas why she might be acting this way would be greatly appreciated.

ANSWER: Hi

She  could be pregnant.  This would be a shame at her young age. Rats can get pregnant from 6 weeks on.  Gestation is 21 to 23 days. Usually they take on a pear shape in the abdomen a week before birth. They begin to nest and may become a bit protective by being aggressive which may explain the biting.   DO NOT let her use paper towels or toilet tissue to nest with. This may suffocate new babies if it gets wet. Fleece or cut up tee shirts only. Towels etc...are out also because the threads can wrap around tiny limbs and cut off circulation on the new pups.

Please refer to this site for tons of info on birth and also how to be sure the new babies are eating and healthy. Learn how to note complications as well.

Also please let me know your location so I can locate a vet and an emergency vet just in case you would need one during birth etc... rather than have to scramble to find one. later

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

QUESTION: Thanks so much for your reply.  I don't think she's pregnant, but I guess we'll find out in the next day or so!  After I sent the initial message, I got her out of the cage again and she sat on my chest and let me pet her and didn't move for an hour!  She's definitely growing, but I don't think she's taken on a pear shape.  My husband seems to think she was more like 4-5 weeks old when we got her, not 5-6.  I would appreciate a referral to a vet in the Cincinnati, Ohio area.  Also, do you have any suggestions on training her to climb a pole? We haven't found the "perfect" treat that she "has to have" :) she will climb down it if we start out putting her on top, but we need her to go the other way!  Thanks a bunch for your help!  In case you're wondering, our rat is named Beaucephyllis and she's white with black spots down her back and a black & white face ... adorable! :)

Answer
Dr. Kim Witalis
Avian and Exotic Medical Center
9951 Springfield Pike
Cincinnati OH 45215
Phone:    513-576-1990

Best place for your rats to go!!
As for treats to get her to go up the pole....I cant really help you there. I dont really train my rats to do tricks, except to train them when they are shy or if they bite etc...but I use cheerios etc...