Yesterday my Americana eggs start pipping and this morning 4 hatched. This morning I noticed one more had started pipping and then this afternoon another. The first one is still in the same amount of pipping as it has since I noticed it and the second one has already hatched. The first one is chirping a lot and is able to breath. I don't want to bother it if its ok, but how do I know? Is it normal for some to start first , but end last?