Why do chickens lay unfertilized eggs?

Because they don't have a rooster to fertilize them?

When a rooster actively mates the hens the eggs produced can be fertile for as long as 2 - 3 weeks at a stretch.

No rooster no fertile eggs.

I think the poster is asking why a hen lays if not fertile.  Like their wild cousins, who make a nest, mate, lay eggs, incubate and then hatch.  They don't lay eggs continuously.  (Am I right?)

Breeding for egg laying traits resulted (over time) in chickens (as well as some breeds of ducks) laying all the time.

But will an unmated wild duck still lay a clutch and try to hatch out unfertile eggs?

Domestic poultry have been bred for certain traits and characteristics as we humans pick and choose. The same as some strive to develop the perfect color and plumage on their birds others strive for the highest in egg laying. Some get lucky and develop both in a breed. Some you get one or the other.

Lots of bird will lay without mating. Even parrot and etc.

The longer spring daylight triggers the egg laying in the hens,even if no male around. Quail, pheasants, and etc.

Now some birds may have to mate to lay. But not all, my guess those that dont pair up would lay with or without a male.

There are a number of reasons but really depends on what kind of chicken. My cochins and silkies are so fluffy i have to AI a lot of them. One of the most common problems i chicken mites. They chew up the vent and make them sore. Sometimes the rooster is infertile but not very often.

Know wild pheasant will lay with or without a rooster pheasant.

Yes, chickens, ducks, turkeys, geese, etc - poultry females will lay eggs and go broody even without a mate. They will do their best to sit and hatch unfertile eggs. The absence of a mating male really has nothing at all to do with the hormonal influence and natural instict.


There is a phenomenon that is rare but does happen and has been proven in laboratory testing. Some unfertile eggs can begin to develop.