I found a duck egg

[brittneyyy]

So in my front yard by a tree stump a duck laid her eggs, a few days ago they all hatch but 1. The mother duck has not came back to sit on it or anything. So I did the water float test and it turned out everything is okay with the egg. I brought it inside made an incubator and place it in there. Am I doing the right thing?

 

[oldhenlikesdogs]

I would discard that eggs, it didn't hatch because it wasn't fertile or something happened to it and it died. It could explode if it's rotten, or at least stink really bad.