I have 3 broodies (Black Australorps) who have been collectively raising 6 chicks together. All of the broodies are 1st time mothers. I noticed about a week ago that the broodies stopped paying close attention to the chicks. For example, they would walk off and if a chick didn't follow, it was like "oh well... Too bad." Then I noticed that instead of all 3 broodies jointly working together, it became just ONE broody who was looking after the chicks. Tonight I noticed that even she seems to have abandoned them. It is nearly dusk. I still have a few random chickens hanging around outside the coop but all of the broodies are inside and up on HIGH roosts where the chicks could never follow. Until tonight at least 1 broody has always stayed in a ground level nesting box with the chicks. Needless to say, all the chicks are outside the coop just running around unattended. Is this normal that a broody would stop mothering her chicks after 3 weeks?