I had heard the horror stories about how chickens are the nastiest animals--they stink, they smell, etc. I was pretty surprised at how fast my 5 chicks (4 weeks old now) can mess up a clean brooder. My husband was kind of enough to give me the "I told you so" talk. We have our chicks in an extra large dog crate, which has been reinforced with hardware cloth to protect them from our fur kids. I start out with a small layer of pine shavings, fluff them up daily, & then add more as needed. Smell has never been an issue but dust certainly is! Keeping things dry (which can be daunting with active chicks) & well ventilated is key, in my opinion. I clean my brooder out once a week & have had no problems with illness, smell, etc.