I have three girls, two of them live together and the other was in quarantine for lice. She is a rescue, she was surrendered to my local pet shop in a tiny cage by herself. She is an absolute sweetheart when it comes to people, loves playing and giving kisses. When it comes to other rats, it's a different story. I've attempted 4 introductions now and they all end in her bullying the other girls. She bites, walks sideways, hisses, and chases the other girls until I take her away. Is there anything I can do? Is she destined to live on her own forever or is there anything I can do to stop the aggression? Thank you in advance.