Mama Heating Pad won’t keep any area - no matter how confined - warm. A mother hen doesn’t warm the entire area, either. MHP (and Mama Broody) work by warming the chicks directly, which is why you want it at the level of their backs.
We stood our old wooden brooder box on end out there just to block the cold Wyoming north winds, not to actually hold in any heat. That was the most logical position to put the chicks’ pen because it was nearest the outlet Ken had installed out there. It was our first year brooding chicks outdoors and I was still a bit of a Nervous Nellie. Frankly, while I had a ton of faith in MHP, I was still uncertain if this outdoor brooding thing was going to work, so we had a backup plan in place just in case. But it did work, and it worked so well that I’ve never looked back.
After that first batch of chicks, we reinforced the plastic on that end of the run for more wind protection, but still just left the box in. The top was a convenient place to store chick food and grit, and we also attached that end of the plastic overhead netting to it. We had one pesky hen that figured out she could fly into the chicks’ brooder pen, but couldn’t gain enough momentum in that confined space to fly back out so that was done to keep her out. The box gave us a place to staple the netting, and we stretched it over the top of the pen and attached the other end to the end of the brooder pen with zip ties.
So technically speaking, the box was just convenient, but by no means necessary. Eventually one side of it starting getting weak and we feared a collapse, so it came out. The last 4 batches of chicks didn’t even have the box up against the north wall anymore, just the wire pen. Hope that helps!
