How are hen eggs fertilized?

Here's the breakdown:

* Chickens lay eggs even without a rooster present. These eggs are unfertilized and are what we typically buy and eat.

* Fertilization happens when a rooster mates with a hen. The rooster's sperm fertilizes the egg inside the hen's oviduct before the egg is laid.

* Fertilized eggs have a small, dark spot called a blastodisc. This spot contains the embryo that will develop into a chick if the egg is incubated.

So, while chickens lay eggs regardless of mating, only fertilized eggs have the potential to develop into chicks. Unfertilized eggs are still nutritious and safe to eat.