Since the snow and cold our 6 pullets spend more time cooped up. Our coop is pretty well insulated and ventilated. We use the deep litter method and it was changed out recently (about a month ago). The previous litter was good from Sept. 'til mid Jan. Never had even the slightest smell, until a couple of days ago I noticed the smell so I opened the windows to get even more ventilation. Will this help to freshen the air?Or am I doomed into changing out two bags of shavings after only a month? THANKS