Talking standard size chickens, how many eggs do you usually set under your hens to effectively incubate? How many eggs is too many? This is a poll, and there are no wrong answers. Just curious what you think. A wild mallard duck (roughly same size as a small standard chicken) who hatched a clutch of eggs in my backyard this spring incubated 10 eggs and 7 ducklings hatched. Is mother nature's number, the magic number 7?