nesting and biting

Question
QUESTION: Hi,
 Well, I've been having problems with my eight month old. She's albino and lives in a large cage with her two sisters. she is rather large compared to the other two and lately she's been nesting, she tends to fight with the others and she bites. it started out with just light nipping but the pressure has increased, it started to happen about two weeks ago. we put it off thinking that she thought we had treat, but we don't feed treats through the bars. is she in heat or is there something else wrong.

thank you, samantha

ANSWER: Are you sure she's had no contact with a male? Generally does nest and become aggressive just before they're ready to have a litter..

Otherwise, no, it isn't heat.. but it may be hormones and she may be a bit PMS'y.

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

QUESTION: thanks. no she's not pregnant. she's nested once before. she takes a bunch of the bedding off of the bottom floor moves it up to the third floor and when the her sister's approach her she'll fight with them. and it only lasts for a week at the most, she did it again four days ago and she quite yesterday. plus now she bites rather hard. should i be worried that her biting is hereditary?

Answer
That's very odd.. I honestly don't know how to broach this behavior. How do you react, when she bites? Do you exclaim loudly, or do you ignore it? I find that my rats don't realize they're biting hard until I "yipe" when they bite down -- and then they back off. Although if she's protecting her nest, she means to bite hard. And no, I doubt its hereditary.. I've had some very sweet females produce some very nasty offspring, and vice verse.

I'm kinda stumped here.. have you tried posing this question to Sandra Todd? She's very good with rat behavior, she may have some insight!