chin change of behavior

Hi, recently i adopt another chin to accompany my original chin, of cause they were seperated in different cage. My original chin changes it attitude toward me. She use to be attracted to treat and i always use treat to lure her back to her cage. But now she has no interet in treat and bite me when i feed her. I always feed her 1st, so that i do not have the smell of the new chin. Please advise me with the current stituation.tnx