Kitty litter boxes with those snap-on tops are great for broody hens. I use wooden boxes that I bought at a craft (like Michael's, AC More, JoAnn's...). I have used milk crates which I really liked... they were the right size for large hens, had excellent ventilation and were deep so the hens liked it. 1/2 peck fruit baskets work, as well as stall-corner horse feeders. I used an old metal wash tub once which was great. I filled it with straw and sometimes there would be 3 hens laying together.