I had 2 ferrets both un neutered that lived together happy for 6 years and never used to fight and my friend also has 2 males that aren't neutered that live together and they don't fight either, just got 2male kits both brothers and not sure weather to get them neutered or not, as I've read up on it and it can cause adrenal disease later In life, so id rarther not get them done, and advice is apprichiated thanks