I don't mind the smell at all, but my nose isn't exactly sensitive. I had 10 sick broiler chicks in the dining room for a while as they recovered (from a vitamin deficiency... good times) and they didn't even smell bad, as gross as they are. But that was only for 3 days and they were still pretty young. I think it depends a lot on giving them enough space and enough bedding- I had 25 broiler chicks in the 3x4 dog crate for one week and yeah, it got pretty gross. But the first 7 I brooded in the same dog crate didn't make near the mess in the four weeks they were in it- I didn't have to clean it at all the entire time they were in there.