I went to check on the eggs this morning and let some air circulate. One of the eggs is turning green. The whole top of the egg that is not buried in the vermiculite is green. I tried wiping whatever it is off the egg with a paper towel, but it wasn't coming off. One other egg is starting to develop this green coloration in two small spots. The temp is steady and the humidity is fine. When you lift the egg out of the vermiculite slightly, the underside of the egg is a creamy white. So what is this and how do I get rid of it?