Independent from the presence of a rooster, healthy female chickens, commonly known as hens, are able to lay eggs at least once a day when they reach maturity after six months.
The only difference brought about by the absence of a rooster is that the eggs will not develop into a chick.
If a hen is able to mate with a rooster, this will result in a fertilized egg. However, fresh eggs may be consumed whether or not they have been fertilized because they’re both alike in flavor, consistency, and nutrient content.
To find out if a freshly laid egg is fertilized or not, hold the egg against bright light and examine the contents for shape and opacity. Early stages of the embryo and blood spots are usually visible, but it takes a trained eye to see the difference between fertilized and unfertilized eggs in this initial stage.