I had problems with one of my rats being super aggressive. Lately it has been getting worse. She is starting to lunge at people when they just come up to the cage. Even during free time she will bite people's feet if she can get a chance. Not a nibble but chunk from your skin type bite. I have tried for over a year to socialize her with no luck. My other rat is sweet but very timid since she is usually picked on by the other rat. I made a decision to separate them. I am going to try to find the shy rat some new cage mates, but I am not sure what to do about the aggressive one. I hate to leave her by herself but she is hurting the other rat now. I guess I am wondering if I am doing the right thing.