Here's a list of facts first: 6 eggs started in a homemade forced air incubator. Temps kept at 99.3-99.7, humidity at 40-50% for first 18 days 1 egg discarded for being clear at 10 days Remaining 5 developed normally, except one had a larger than normal air cell ( Egg 5) Day 19 - Humidity up to 60-70%, temps at 99.3-99.7 Day 20 + 3 hours - Egg 1 - first pip, but at wrong end Day 20 + 10 hours to Day 21 + 2 hours - Eggs 2, 3, 4 pip, 2 & 3 at wrong end Day 21 + 12 hours - Egg 1 zips, tries to get out for over 3 hours, I help it out at that point by popping off the end he has been pushing at for so long Day 21 + 13-16 hours - Egg 4 (correctly pipped at large end), zips and hatches, no problems Day 22 + 2 hours - Egg 2 zips and hatches, no problems Day 22 + 6 hours - Egg 3 zips and hatches, no problems Day 22 + 10 hours - Egg 5 - still no pips, no movement, no peeps - Candled and broke into air cell, removed shell and examined dead chick. Head appeared to be at the air cell end. Yolk not absorbed at all. Blood vessels shrunken? Appears to be fully developed, but maybe Day 18, or 19 when died. Noticed odd lump on belly, right above left leg. Excised lump. Didn't look like any of the organs I am aware of (and I've butchered several chickens befor). Could feel hard lumps within it. It was about marble size and yellow. Opened it up. No smell of infection, but had a lot of yellowish material in it, kind of like feed that is not all digested yet. So, opinions everyone? Things I am wondering about: Why did 3 of 4 eggs pip at the small end? Was this hatch considered late? I see so many on here who have chicks hatch at day 19 or 20. Does anyone know what that thing was in the dead chick? Tumor; organ chicks not hatched have, but not adult chickens; infection pocket; something else? Thanks for everyone's feed back. I am aways looking to improve my hatches and learn new things from you guys on here.