How do chicken eggs work? When do they grow?



So humans are born with all of their eggs, I’m assuming that chickens are born with all their eggs as well. With humans your eggs are tiny and “grows” when it’s fertilized as an embryo but obviously when chickens are born they’re smaller than the egg themselves. So how in the world does this work, an adult hen isn’t just composed of dozens of full sized eggs.

In: Biology

The embryo is a similarly microscopic thing for chickens and works similarly. Fertilization has to happen before the egg formation. The chickens body builds the egg around each embryo to be a source of nutrients due to the lack of umbilical support. It’s a cycle like periods in humans, except instead of ending in a bloody mess if it isn’t fertilized the egg still gets built.