Hi everyone I am adding two male rats to my mischief. I am receiving a two tier critter nation cage and was wondering about introductions. I know the different methods of doing it however I was hoping to get advice. I am introducing two 6 month old male dwarf rats to two 1 year old male Standard rats. I was wondering if I should keep the cage separate and rather allow them to have their own teir, or is it safe for all of them to live together? I don’t want any of the rats getting hurt. Thank you!