I have lost too many chicks "waiting" on them. I just had a hatch of coturnix quail, and three or four hatched, and the rest were just pipped, zipped or nothing. I helped the rest of them out (took me about 12 hours to prevent from bleeding them out). Now, all 12 are doing great. I have found that if you have to help one out, then you need to help the rest of them out as well, so I don't pussy foot around anymore, I just dig them out, stopping if there is blood and moving to the next, then letting them all sit for another 3 hours or so, then trying again. This was my best hatch so far, only loosing two developed eggs, who never pipped into the air sack. And, believe it or not, but three or so of the ones I helped, weren't even pipped, and they're still doing very well.