Im not sure if the brooding instict is as strong in other breeds, but today I did some major rearranging in my key west pen. Everyone one in a tizzy. I have a mother/daughter pair sitting on 4 eggs in the same box. They both started on the same day, quite cute actually. Anywho, since they are in a box with tall sides, I know when the chicks are born in a few days they wont be able to leave when the moms leave. So I got them a new broody box with lower sides, took the eggs out and gave the hens a boot. After a few sips of water, a massive broody poop from 1, they both went right back into the new box, clucking all the way. Ive never let any other chickens go broody other than key west chickens so this may be normal but I thought it was pretty impressive the mothering instinct these 2 have!