What is egg candling and how is it done?
After about a week of incubation, you can candle eggs, by making a cardboard cone, the big end of which fits over a strong flashlight. If you hold the eggs over the small hole with the light on (dark room is essential) an infertile egg will appear clear, whereas a fertile egg will be dark looking and will show small veins inside the shell. Those that have died in the shell often appear as a dark line across the shell.
