We have had our flock since Nov 9th of 2011, so they are just over 3 months old. We change their pine shavings regularly, as needed, and everything has gone very well. In fact the coop has really been a pretty sanity place, for a coop, and any smells aside from a slight chicken odor have been absent. We just changed the bedding last weekend, and yesterday, as I opened the coop to let the girls out for the day, (they are free ranged), I noticed a distinct ammonia smell, and this morning I noticed it again? Food and water are ample, nothing has really changed at all... Any ideas about whats going on or what if anything I should be doing about this? Thanks ya'll.