Your hens lay eggs through their cloaca, or what we call the vent. While eggs exit through the same vent used for everything a chicken excretes, the tissue of the uterus extends with the egg (a sort of inside-out trick) until the egg is entirely out of the vent.

Where will my chickens lay eggs?

Although hens typically prefer to lay eggs in nests, it is not unusual for some eggs to be laid on the floor of the hen house or on the ground.

Do chickens lay eggs out their bum?

When the process is complete, the shell gland at the bottom end of the oviduct pushes the egg into the cloaca, a chamber just inside the vent where the reproductive and excretory tracts meet — which means, yes, a chicken lays eggs and poops out of the same opening. But not at the same time.