One of my broodys starts plucking her chest feathers early but that's just one possible sign of broodiness. Other signs would be: not wanting to leave the nest box except for short breaks, trying to return to the next box immediately if they're removed from it, puffing up like a turkey, flattening down over eggs like a pancake and hissing, a chuck-chuck-chuck call.
If she's just hanging out in the box she might be thinking of going broody, or she might just be a nest box lounger. You'll know when she's committed when she shows multiple signs from above, mainly the first one, that she simply does not leave the box except to eat, poop and furiously dust bathe.
If she's just hanging out in the box she might be thinking of going broody, or she might just be a nest box lounger. You'll know when she's committed when she shows multiple signs from above, mainly the first one, that she simply does not leave the box except to eat, poop and furiously dust bathe.