We used to have 2 gerbils (both male). One died a few days ago, so the other one is now on his own, which seems really sad. I have read contradictory things about introducing another - would it be safe to do if I bought another young male, should I keep them in separate cages to start with and swap them about so they get used to each others smell? Some things I have read seem to suggest that is it is a young male it might be OK to just put them in together?