The eggs are not alive with a duckling until one of your ducks decides to go broody, once she makes that decision she will start sitting on her eggs, probably at night till she has what she feels is a good # to sit on, then she will be gin to sit around the clock except to get off maybe once or twice a day to eat. swim and poop then right back on the nest she'll go. After about 5-7 days of her sitting constant if you candle the eggs you'll see the begining of veins growing and that is the begining of the duckling. She is not letting the eggs die just because she isn't ready to sit yet.
Your not giving your ducks a chance to go broody, leave the eggs and wait, thats about all you can do at this point. she'll either go broody or she won't, like GQ said most Muscovy's are great brooders and mothers, but theres always the exception. but I think if you'll be patient you'll get a broody, I have 10 ducks and so far none of mine have shwon any interest in brooding, last year we already had duckling, so patience is the word here. Give them time.
