They won't always roll them out or eat them.... but it is something that some broodies do, so it is worth mentioning as a probable reason for disappearing eggs under a broody. If all hens did it then 'exploding' eggs wouldn't be a potential hazard, and folks do have that happen once in a while.so if any eggs that aren't growing a hen will eat or roll them out of the nest? and if you mess with a broody too much at the being of being broody will she stop being broody? My hen been was still on the nest of eggs when i got home yesterday so i think she went broody and i marked the eggs and gave her more food and made shire she knew their was food and water there. i did that by putting my finger in the water and making nose with it. did the same with the food. she did get off the eggs but only to dust herself then she got right back on the nest. sorry if it is a stupid question.
To reduce the potential hazard of eggs going bad some folks candle the broodies clutch and pull ones which are duds, doing this or not is a personal decision/preference. I usually just candle around day 10 and pull any clears but I don't get too worried if I don't get a chance to do so.
Some hens are easily broken if you mess with them, others are rock solid from the first day they park themselves in the nest.... this is another of those things that just depends on the hen's personality and there is no clear answer to.