I separated them so they wouldn't attack each other and when they see each other, they bite the cages. I tried to introduce them to each other but i don't know how. Do I have to make a big house for them so they would not fight? They're both boys actually. And do they have to live in a pack or something? I'm trying to introduce them to each other because when i get a female hamster, i'm gonna use the other cage as a breeding cage or make a bigger one. Please answer.