Hi all, I've gotten some great advice in the past about some mold issues in my coop. Tonight as I was leaving them some rice and spinach I couldn't decide whether to close them up (window and hatch) or not. I have an insulated coop (8x6 foot). There is a bathroom fan running all the time. There is a window (too small) and a hatch door to a completely caged in run (raccoon secure). Last fall and winter I had 9 sub-adults (male and female) with no mold problems at all. Some were rehomed, more bought and now we have 8 laying hens. This summer was really humid and we had our first mold problems. I added another small fan to circulate air around inside the coop and made sure I left the window and hatch door open all the time. Cleaned out all the shavings and washed the walls down with bleach. Not enough, more mold. I put in a 100 watt light to warm it up a little. We had mild improvement, then weather cooled and we had no trouble for about a month or so. I went out yesterday to the worst mold yet. We had some rain (fairly heavy rain) and my hens are doofuses who don't seem to notice rain. They came back in teh coop day after day soaking wet. I again bleached the coop all out, fluffed the wood chips and ensured nothing was wet. I just put in a droppings board... might this contribute to moisture since it's not absorbing into the wood chips? We're nearing our first snow and nights are around freezing. I read some info describing summer mold as being due to insuffucient ventilation, and winter mold being due to daughts (too much ventilation). I remember walking into a fish store in February. Walking into the hot humid store and bringing in all that cold dry air caused thick fog in the entrance, dripping from the roof. I'm wondering if I should close up the window and hatch when it's cooler outside than inside the coop, and opening as many vents as I can when it's warm outside. I turned on their heat lamp hoping that the heat, the ceiling fan and the small circulating fan will keep the moisture better controlled inside (I read something about moving air and heat compensating for a considerable amount of humidity). We're probably going to start cutting holes in it next spring but didn't think we needed to this winter. To sum up, the root of what I'm asking is, when it's near freezing, do I keep vents open, or close them up? Sorry this is so long... it seems kind of complicated to me and I've been thinking about it a lot.