Does an Older Male rat need a Companion?

Question
Hi,
This week I am getting a male rat (I have never had a rat before) from a vet school.  He is about six months old and has always lived alone.  Originally I was going to get a pair because I read that they like friends.  However, I also read that older males don't take well to be introduced to new rats, and since I am new to this I am afraid of screwing up and one of them would get hurt.  So my question is, should I leave him alone like he is currently, or introduce him to a new rat friend.  He's going to be a class room pet in a Science Room.  Thank you!

Answer
I think it would be a good idea to get him a friend. He is still young enough that bringing in a younger rat, about 3 to 4 months of age, and letting them sit side by side in their cages for a few weeks to get used to each other before introducing them, would be ideal for the older rat. He may get lonely by himself in a cage.  Its not healthy if they are stressed as you know since this can lower the immune system.  People think male rats are really aggressive when, if  bred properly, they are just as sweet as can be even with other males.  If worse comes to worse, you can neuter them both and this would cure any aggression should it arise, but chances are it will work out just fine.

I am not sure who said that 6 months is an older rat, because rats are now living much longer than they were even 5 years ago.  Proper diet, keeping them in nice spacious cages, using the proper litter that is safe for their delicate lungs, and learning about common ailments so you can recognize them early enough to seek veterinary attention, they are living to be 3 years old and even older.