So I collected some duck eggs from near a pond that I wanted to try and incubate. I noticed that some of them have small dark spots on them. You can see them from the outside. One had a lot, so I broke it open and found these dark blobs. The egg looked fine other than that, it wasn't watery and the yolk didn't look too old or spoiled. Does anyone know what this is? Should they be tossed or can they still be incubated?