Jail Birds !
Banty hatchlings in my newly-built brooder. It has removable panels on 1 side, door and top that can be installed/removed as ambient temperature dictates. For cooler temps down in the barn I even add one more heat lamp. The heat lamps are on simple dimmer circuits I wired up so I can have better control over the amount of heat the birds are getting. Brooder is 2' deep x 3' wide x 2 ft high and is made of 1 sheet of 1/2 inch plywood. Add some 1/2 inch hardware cloth, hinges and a latch and you're in business. I'm going to make a few more. They're easy to move around or even hang on the wall.