Quail size chicken egg?

[Apache12]

 

[Apache12]

meant to add info. I have 2 black Australorp they are just over two. Healthy happy and great egg layers. But this is a first what causes this? Only change has been some heat increase.

 

[rosemarythyme]

Fart egg, and they can just happen.

 

[aart]

Probably just a glitch.
Open the egg up and see what's inside.
Fairy, fart, wind, rooster eggs are usually from a tiny piece of tissue breaking loose from the reproductive tract, or an immature ova(yolk) and the body forms an egg around it. Color can be darker than 'normal' as the pigment coating released has to cover a much smaller area so is thicker. Can happen with any age layer, but more common with older layers

 

[Apache12]

Fart egg. That’s funny