How can you tell the difference between a green chicken egg and a green duck egg? I thought I had some hen laying beautiful green eggs, because they were in a nest with some brown and white chicken eggs. I also have Runner ducks who lay green eggs, but these aren't as big Hershey's eggs. I caught a duck sneaking out of the nest so now I'm not sure if they are chicken or duck eggs! Is there a way to tell visually?