What I usually use as a brooder is a huge cast iron bathtub in the barn. With 40 chicks though, it just wasn't big enough. I am using one of my small winter pig pens for them. There is a heat lamp on one end, but it is off during the day since it is so hot here. They do go under it over nite. But they aren't all huddled up. They are so dang cute that I find myself making extra trips to the barn just to watch them.