Cloaca: The cloaca is the only hole for the reproductive and digestive system of a chicken. The cloaca, also known as the vent, is where chickens poop from, where the eggs come out, and where they mate with a rooster. Yikes! This may bother some people when thinking about eating their eggs. However, no need to fear. When laying an egg, a chicken’s vagina flips inside out of the cloaca, so the egg never touches the poop area to become contaminated. Whew!