alone rat

Question
I have recently brought a 5 month old male rat.I've had two male rats in the past and one of them attacked the others neck.Would i be able to introduce another rat with the one i've brought without this happening again?

Answer
 It's possible, but with males it can be tricky.  Your best bet would be to get a very young male, 6-8 weeks old, and hope that the older male will be able to dominate him easily and settle their pecking order without fighting.  Neutering can also help a lot with males living together without fighting.  Sometimes males simply prefer to live alone, however, and you'll have to be prepared for this if you want to get another rat.  Sometimes a good idea is to get two baby males and if the older male doesn't get along with them they can live together in a separate cage.

 Making sure you follow proper introduction procedures can help them get along better.  Start with letting them meet on neutral territory, somewhere the rats don't normally play.  Giving them all a bath first can help mask scents and help things along, too.  If they are doing well, clean the cage and put the new rat in first, letting him sniff around and mark his territory for about a half hour before putting in the other rat.  Some fighting is to be expected as they sort out their pecking order; only separate them if they are being vicious or drawing blood.

 I hope this answers your question, good luck with your rats!