I think they are just have a normal molt. But do give them more opportunities to occupy their little chick brains. Some folks hang a cabbage just out of reach, so the birds have to jump up to get some. Give them a brightly colored small ball and they will end up pushing it around. Even "parrot safe," toys will provide amusement.
If they are too crowded they may begin feather pulling out of boredom and lack of room. Give them a real tree branch to explore, etc.