So far I have had 5/11 eggs I put in the incubator hatch. On day 20, I had one egg that had pipped and hatch on day 21. Early on day 21 I had another pipped. The one that pipped was chirping and seemed to be doing fine. When I came back later that evening to check on the chick and one pipped egg, I noticed the pipped egg had stopped breathing and had yellow gunk around the opening. Can anyone explain what happened? All the other eggs hatched fine. I'm currently on day 24 waiting to see if the other 5 hatch, if nothing by tomorrow night they'll be discarded.