I have Ancona duck eggs doing this to me right now! Two days ago everyone was peeping and shaking in the shell. Then yesterday one had pipped, but the other three were turning dark blueish black inside the shell. When I candled them I could no longer see movement. It was just one day earlier they were cheeping and rocking. There is no smells. Should I leave them a day or so and see? Is it possible that they just are to big to see movement now? I could have swore I saw one twitch while ago, but now I think I may have wishful thinking! I don't want the one duckling to grow up alone!