I'm a kindergarten teacher who is new to this egg hatching thing. Our science resource center sent 28 eggs to me in an icubator that has a thermostat but nothing to display humidity levels. I placed the eggs in the incubator on their sides on this past Monday. The eggs have been kept at 100 degrees and turned 3 times daily. My problem is that I smell a slight odor when I open the incubator. Today I used my hubby's maglite to try to candle the eggs to see if I could find a rotten one. I don't really see anything but yolk (which looks bigger than a normal yolk) I am not seeing veins or a black spot of any sort. There is a definite air sac in many of them. A few of the tiny eggs look as if they have a larger air sac than the others. Many of them look pock marked and a few look cracked. I don't want an exploded egg, but I don't want to kill a baby chick either!!! Some eggs are dark, some light brown, and some green. The light brown and green eggs are small. Any advice on what I should be looking for? Am I just missing the veins, is it too early to give up one them?? Sorry about the rambling, PLEASE HELP ME! I have no idea what to do.