I've just taken on a male dumbo rat "Bobby" who needed rehoming because apparently he had a cold when he was a baby and the owner didn't want to keep him! I've been told he's around 4 months old.

I'm looking to put another rat in with him but really need some advice as to what's the best thing to do. It's been suggested that I have him castrated and then put a female in with him. Or maybe put a younger male in with him who hasn't reached maturity.

Can anyone shed some light on what's the best thing to do for Bobby as I'm really concerned about him being alone for too long.

Thank you.