Moving all her eggs from her nest after sitting for nearly three weeks?

We have a barnyard mix of 8 ducks, and our Khaki Campbell is broody, sitting on about 30 eggs, that her sisters have also contributed to. She has been sitting on the eggs for nearly three weeks now! The last two days though, in the morning, when we come to let them out of their house, ALL the eggs are moved into the MIDDLE of the house, and she looks very confused. She goes out for a minute eats and drinks and then comes back in within ten minutes or so. The first day, I immediately made her nest back where it was, and put all the eggs in the corner, and she sat on them ALL DAY LONG.

Then THIS morning, my husband suggested that we not touch the eggs and see what she does. She went in and out, in and out and in again, and just seemed like she was overwhelmed and didn't know what to do. So about ten o'clock, without further delay, I went and made her nest and put all the eggs back in there, and she was in there the whole time, watching me, and then immediately sat right back down on the eggs.

We're thinking about getting a game cam inside the house so we can see what is going on in there in the wee hours of the morning. Has anyone ever had this happen before? We're so sad, because yesterday, one of the eggs cracked during the ducks rush out of their house, to go jump in the pond, and there was definitely gestation happening in the egg. What's going on? Why are all her eggs being moved out from her nest? Why NOW? Could it be a potential black snake that's scaring her to move her eggs? We haven't seen any yet this year, but it's possible.

 

Thank you! Yes, this morning, she had only moved 14 out of her nest, and I candled them, and see that 9 of them were totally dark inside. I don't know how to candle effectively, I'm not sure what is a rotten egg or what is actually a gestating duckling. None of them smell. Also, I wonder how long they can stay out from under their mother before they can't gestate anymore? I did take the five away and think I will look at the others if she gets up again. We are going to add a wall inside to create a box for her, in her corner, so maybe that will help her out! Thanks again!