Feral rats and biters

Question
I have a rat that I brought home from work (major pet supplier) who had been in the wellness area for several months. She was not a biter when she was being treated but has turned into an aggressive attacker since I brought her into a home setting. Recently we had a rat that was loose in the store for several months (feral I think), caught, and they asked me to bring her home due to the fact that they were not sure of her temperment. She has been "tasting" me since I brought her home, but tonight bit me aggressively when I was trying to get her out to clean her cage. I am not interested in having them put to sleep but are there any measures I can take to change these aggresive patterns? and if not, is there any rat rescue organization that handles aggressive rats? I have seven of the most loving rats on the planet and appreciate the individual personality of these little "people". I don't want to put them down so if they can live two physco rats together I would that, but would rather reform them to live with all of the rats. Thanks for any help you can give me and them. Dot

Answer
 From the experience I've had with aggressive rats, it doesn't usually end well.  It all depends on why they are aggressive.  It can be hormonal aggression, though this is more rare in females, and spaying may or may not help.  It could be cage aggression, where they are simply protecting their cage.  I believe it is most likely lack of socialization that makes them aggressive.  Just because they are aggressive to you doesn't mean they will hate each other, you can always try to introduce them and see if they will get along.  Start on neutral territory, leaving them together for about 30 minutes, then clean the cage they are going into to remove all smells.  Put the less aggressive one in first, and leave her there for about half an hour before putting in the other one.  Some fighting will occur and that is normal, only separate them if they are drawing blood or being very vicious.  Bathing them or otherwise masking their scent can help them accept each other, as well as having a large cage so they each have enough room for themselves.

 They may also settle down with time and gentle handling, once they realize they are no longer in a bad situation.  Some rats turn around, some don't.  If you work with them, giving them treats, petting them carefully, they may become less aggressive.  If not, and you don't want to put them down, there's no reason they can't just live out their lives without much human contact, obviously they don't want it.

 Well good luck with your rats, let me know how it turns out!