Anytime I mess with any of my Duck's nest they don't like it. Some people can candle the eggs and such but mine try to bite something fierce and hiss. Once I get them off of the nest using something I can get the eggs if I don't want them to go broody. I guess it would be possible you touching the eggs would disturb her. It would just depend on the nature of that particular bird. Mine would be upset and probably leave the nest due to how their behavior is. That is how I have been able to stop my others from becoming broody. My Ducks that have this behavior are my Mallards and Muscovy. I was never able to catch them off of the nest to ever do anything with their eggs.
She definitely pecked me when I was placing the LF eggs. What I don't get is why it took her 9 days after that even to decide she's done with it. Oh well, she is a baby though, and those are really spontaneous with their hatching, so as long as she's healthy I can't be mad. I'm sure her or Ursula will try again soon. And for now, I'll shut up about my problems and cheer yalls on. And who knows, if @junior67 does a July hatch-along, I might be in it
