I have a Q for our group. I hear so much ONLY use a pencil to mark your eggs. The Q comes in my mind, what happens if you use a crayon? A marker? etc. I understand that the idea is to keep the egg healthy. You don't want to indroduce contamination, chemicals, and what not into the developing embrio. Then my mind goes to those Easter Chick pictures that I have seen where the whole embrio was colored w a dye that is injected into the egg. See for instance: http://www.urbanext.uiuc.edu/eggs/res32-qa.html where is says under Q # 90: 90. How do you color embryos? To color embryos you inject a colored dye about .2 to .5 milliliters into the egg with a hypodermic needle near the bottom of the egg. Now I am thinking, I have left over easter egg dye (yah, I know, I'm a bit slow to clean up the craft table)- NO not to inject - but can I dip one side into the dye, to tell the different breeds apart in the incubator? I just got silkie and cochin eggs, and they look similar to me. If I made some yellow or orange, I could tell them apart.... What do you all think? And why can't I use a marker or crayon? Thanks!