Hello Maria. Can you describe to me exactly what you mean when you say they act stressed? When you had them separated, were the cages still close together? Could they still see each other? When they are all three in one cage together, do you see any kind of fussing or fighting, one chasing another, one plucking at another, anything at all like that? Please give me the measurements of the cage they share. This extra information will help me give you my best answers and guidance with this. Thank, Patricia