What is the safest way to mark your eggs for imfo? About 4 or 5 years ago my faimily went out fishing and found a handful of wild geese eggs. We took them home to hatch. Then after they hatched, within a few days we released them back into the wild. Before we put them into the bator, which was a round metal bator. It kinda looked like a Brower. It worked really good! 5 eggs total but only 3 or 4 hatched. Not sure how many. Its been awhile and I kinda been drunk way too many times since then to really remember that well. But anyhoo! I used a black sharpie to write on the shells the date that we found them to give us an approximate date to look at when the time drew closer for them to hatch. Is using a marker harmful or is there another way to mark them so as not to poison the little guys and gals?