dominant male rat?

Question
Hi :)
Was wondering if you could help me. I have 5 boy rats, currently 3 together, 1 newbie who's currently doing introductions with the 3, and 1 who's on his own. The one on his own Bertie, we have tried introducing him to the trio, but he just gets fluffed up and aggressive, rather then showing "who's boss". We tried introducing Bertie to the newbie Ernie, but within 5 minutes of putting Bertie in the bath tub (meet on neutral ground) he fluffed up and started aggressively biting Ernie in the side, making Ernie extremely scared. I was told to get him neutered and introduce him to 2 female babies, but I'm worried that neutering wont work, as I know he's anti social with other rats, but he's not aggressive with us, so I don't think he'd have an aggressive nature? I was wondering what you'd advice, as I'd love to be able to have all my boys together, and Bertie less lonely.
Hopefully you can help,
Katie

Answer
Neutering does help....I have had to neuter two males out of all the males I have had and still have males (no girls at this time due to mammary tumors which is why I avoid females till I can get all females spayed at once)

My two males fought each other and the other males and once they were fixed they were like new rats. They still had it in them to wrestle and defend themselves, but they did not start the fights like they did before.  

Neutering and putting him with females would be good but NOT female babies. Males, neutered or not, are a threat to baby rats, period.
Maybe females that are 3 or 4 months old but not much younger than that.

I have also had males live alone by their own choice,although they were not neutered at that time, they just hated other rats and were more happy alone. Contentment showed by their weight gain (they lost it when they were with other rats) bruxing, more energy and all around well adjusted once they lived alone.  MOST of the time, rats do better in pairs or more *I dont recommend more than 3 to 4 intact males in the same cage no matter how big the cage is)

Anyhow, bottom line is, I would opt for the neuter by a qualified experienced vet. I am sure it would make a big difference!