If you’re thinking about hatching some chicks from your backyard hens, you’ll need to make sure your eggs are fertile before popping them into the incubator. So how can you tell if your eggs are fertilized? Take a look at the yolks in the photo below. Fertilized eggs have a blurry, bulls-eye spot on the yolk. Unfertilized eggs still have a white spot, but it’s much sharper and smaller, like a pin point vs bulls-eye.
As a general rule of thumb, you’ll need one rooster for every 10 hens in order to keep your eggs fertilized.
Interesting Facts About Chickens & Egg Fertilization
- After mating one time, the hen can store sperm in her oviduct for up to three weeks, fertilizing eggs as she produces them. In most cases, fertility levels will be ideal for about 3-4 days after mating.
- Chicken eggs have a protective coating on them that prevents them from spoiling. After an egg is laid, it can remain dormant for up to two weeks.
- A mother hen will wait to sit on her eggs until she decides she has a large enough pile of them stored up. Once she begins sitting on them, (or they go into an incubator) the dormant eggs “activate” and the chicks start to develop.
- Chicks typically hatch 21 days after incubation begins. I’ve had a few hatch a day early, and some hatch up to three days late. Chicks hatch fully feathered, peeping, and running around, ready to eat and drink.