2 male finches and 1 female

Question
I have recently gotten 2 male and 1 female Zebra finch (born in December) all from the same parents.  They have gotten along fine, but now the males are aggressive (hissing, and flying at other) to each other, and I am noticing feather loss at the back and neck of the males heads.  The female is fine.  What do I do?  I have purchased a big new cage, 36x32x16 and plan on moving them.  I am not sure about breeding, should I leave the nests out of the new cage?  I am a real amature and need some help!!  Thanks!

Answer
The two males obviously don't get along. Best to keep tem separate or they will kill eachother. If they are from the same parents, best not to breed them.
Note:
While Zebras are hearty birds, they are aggressive by nature.

I would not suggest breeding until you know more on how to.