aggressive rat

Question
hi there i have a 2ish year old dumbo rat, whos brother i have just recently had to put to sleep. the one left is a very large boy hes probably 3 times to size of a young rat.unfortunatly he doesnt get on well with other rats. a while back when his bro was still alive i introduced him to my mums smaller rats, and he sided onto them, then attacked, so i feel he has not been very well socialised since birth (i got him and his bro second hand)
before his bro died, snowy (prob rat) attacked his brother and gave him a very deep gash. to cut the story short :) ive recently brought two baby rats to keep snowy company.this im afraid was a bad idea :( i covered the baby rats in vanilla esense and put them all on mutal ground, but snowy went straight in for the attack, i stupidly tryed to stop the fight and got badly bitten by snowy :(. i tryed again to introduce them but once again snowy attacked. i feel bad as i brought the 2 boys for him, but it seems to me he would rather be on his own?and to be honest im to afraid to try to introduce them again, as snowy is very big and very aggressive, he could quite easily kill one of the younguns. is it ok if he stays on his own?i give him lots of love even if he would rather not be handled. sorry for long letter just hope you can help.
many thanks
jodie  

Answer
 He should  be just fine on his own.  Though it is true that most rats do better in pairs, he is obviously telling you by his actions that he does not want a cagemate.  As long as he is handled daily and given attention he should be just fine.  They may even be able to play together outside of the cage, where most rats are less territorial.  I hope this answers your question, good luck with your rats!