Your brooder box looks all most identical to mine! You, however, have a better lid design. I only made one lid that opens and the other side is just covered with no access. Makes it IMPOSSIBLE to get it clean and get birds out. Good thing I have kids that can climb in! 2 lids is a MUST!! Great job!
Hens go broody when you don’t want them to… and won’t go broody when you do. 
