You need nest box curtains! When you have a broody, you close the curtain so other chickens can't see the broody hen. Broodiness begets broodiness! If they can't see a broody, its a less chance they will go broody by seeing another broody. (Just something I read up on when I was thinking of making neat box curtains)
So true! If I have one silkie or SG start, they all four start within the week. It happened a few days ago, and 3 are already crammed in one next yapping. I did not even include these when I said I had 4---the other 4 are LF in the big house. The silkies I do not even count anymore because it seems to be a permanent condition lol