Well, they are the longest incubation period of like.... any egg. 35 days is a long time for things to go wrong in an incubator. On top of that, they are duck eggs, which require really super high humidity compared to chickens during incubation (like 70-80%), and more specific alteration when hatching (a much lower temp than chickens and a superfreakinghigh humidity, like 90%.... If I filled my incubator top to bottom with water, I'm pretty sure it wouldn't go over 80%, because it's stubborn like that). A lot of people also recommend cooling the eggs for 15 minutes a day for muscovies, plus spritzing them with water (some people will say as many as 3 times a day). So "tough".... well, kinda yes.
