The CLEVER Trick Behind Bird Eggs.

Added: 2026-05-23

[00:00:00]Birds use a single exit door for reproduction and releasing all body waste. This universal opening is known as the cloaca. When an egg is fully formed, the muscular walls of the uterus begin to strongly contract. These internal spasms push the egg downwards.

[00:00:16]Right before the egg passes out, part of the reproductive tract actually turns completely inside out. This clever inversion prevents the fresh shell from touching any harmful bacteria in the waste. The egg safely drops out of the bird blunt end first.