I raised my baby chicks in the basement (unfinished, concrete floor). I didn't put a top on the brooder and sure learned my lesson. Eventually the chicks learned to fly really well. While I wasn't there (working, etc) the chicks would fly to the top of the brooder then fly out and "free range" around my basement all day. Also at night they preferred to roost on the top of the boxes instead of on the roosts I put in there. All of that I don't mind, it was the poo that I minded. But I figured it was the price to pay for cute little chicks who would become pets and makers of fine breakfasts. Until the chicks went outside and I went into picky-retentive cleaning mode in my basement. I used Dawn and Soft Scrub in a warm water basin and used a steel wool pad to scrub the caked poo off the concrete after soaking. All the poo came off, with lots of scrubbing, but it left behind what looks like little poo shadows/stains wherever there was a (significant) poo. Any ideas on how to get rid of the stains? Thanks.