someone was asking about mold in their coop. i can only speak of my own experience. i use the deep litter method in my coops and let the hens turn the litter, the neighbor comes over once its broken down fairly well and composts it further to use in his gardens as i do as well. well, i hadn't cleaned the coops out in about 1.5 years, i just kept taking some and adding some and sometimes when it rains it floods but i figured it eventually dried. about two months ago i decided it was time for total coop cleaning. my brother cleaned everything out and by that night i had a sick hen. the next day she was dead on the ground. within the week i had lost 10 or so birds. i hadn't a clue what was going on. i am the biosecurity queen. it wasn't until a few weeks later that my brother mentioned that that night after cleaning the coop, he had a severe headache, high fever, body aches that all lasted for at least 2-3 days. it was aspergilliosis that had been released into the air as he shoveled out the coops that made him and the birds sick. the spores were down deep enough that they never got to them until the coop got fully cleaned out. no more deep little for me. what a shame. and totally my fault too.