Well done, and well explained! I deducted a star because I think that you could have added more pictures, and could have mentioned other types of brooders like a melon box brooder and a puppy playpen brooder. I also think that it would be good to discuss pet proofing- many dogs and cats have will be inclined to eat baby chicks, and therefore protection is an important part of constructing a brooder. Overall, this is very informative and well written, albeit having a few gaps. Good job!