Ok well my boyfriend has this pet rat and he wanted to to another one for the first one . Now its been a day and frostmourne (the second rat ) Has been biting epic ( the fiorst rat) on the tail. know we seprated them both i it normal for them to do that ?

They might be trying to fight for dominance are they males or females? try intorducing them gradually

Yes, pastience is the key with dominace issues. If this dosnt stop, then I propose getting the one that is biting fixed. This usually fixes the hormones in the boys. Or re introduce them on mutual grounds like a bath tub and dab vanilla extract on thier private areas and head so they both smell the same. Fixing is usually the last resort for a biting rat.

I didnt even know youcould get rats neutered. My vet said they couldnt

Before we got rid of our females we tried to get some one to fix our rats but all the vets we called refused to do it saying that it was too dangerous to the rat(s).