We had a problem with one of the females. Either she or her mate were plucking her feathers. My wife sent her to administrative segregation, and the problem disappeared.
Her former mate is also in a separate cage. He can't seem to get along with any of the others. Now they spend all day flirting with each other, but my wife says it will be a cold day in hell when he will get another chance with her.
Give them some yarn scraps and a bit of hay to make a nest with if you decide not to separate them. Also, do not neglect nutriation. Give them chopped boiled egg with the shell chopped in with it. They love lettuce, but they make such a mess with it. Also, sometime I give them just a tad of macaroni with cheese.
Good Luck,
Rufus