I have a broody silkie bantam. She has been broody on and off for a while. She had been sitting on a couple of eggs (unfertilized) for app. 2 weeks. I purchased some fertile eggs and placed them under her. She was not too fussed with the transition and kept sitting on the eggs. After 2 days she seemed to be getting off them more regulary. Today I went to feed her and she was off the eggs, which felt cool. She was back on the eggs next time I checked on her. How long can the eggs be left for before they are effected.