Duck eggs are a little easier to candle in daylight, if you have a good light — 250+ lumens. (iPhone flashlight works pretty well lol) From the pic above, if you can walk inside there, hold the egg near the back wall, in a dark corner and you should be able to see development. Once you see growth in one, you’ll know if the others are developing or not. But don’t remove any until around day 10-14. This was around day 5 of a duck egg, I believe.