How many eggs does a chicken have to lay before one can hatch?

A single chicken egg needs to be fertilized by a rooster to hatch. A chicken doesn't lay multiple eggs that combine to hatch.

Here's a breakdown:

* Unfertilized eggs: These are the eggs you find at the grocery store. They won't hatch because they don't have a developing embryo inside.

* Fertilized eggs: These are laid by hens that have been with a rooster. The rooster's sperm fertilizes the egg, and if incubated properly, a chick can develop.

So, it's not about the number of eggs a hen lays, but about whether the egg is fertilized and incubated correctly.