Avian messengers, such as PIGEONS, are birds that have been used for centuries to deliver messages. PIGEONS have been used since ancient times to carry messages over long distances, and they are still used today in some parts of the world. They are known for their homing instinct, which allows them to find their way back to their home roosts even when released from unfamiliar locations. PIGEONS have been used in wars to carry messages between troops, and they have also been used to deliver mail.