After long-term breeding and training, even if they are released outside, they will be eager to return to their nests. Therefore, when the ancients went out to send messages, they always brought homing pigeons. Even far away, pigeons can fly back to the station in time to deliver messages.
1. Home: Take a homing pigeon from the post station, and when you need to deliver a letter, tie it to the homing pigeon's leg and let it fly, so that the homesick little pigeon can't wait to fly back to the post station. This is the simplest.
2. Two-point cycle: feed the homing pigeon in place A, but don't let it sleep in the post station in place A at night. I can only sleep in B's post office. During the day, pigeons wake up and fly to A to find food. After long-term training, homing pigeons are used to eating A and sleeping B, and they will develop the habit of running back and forth to deliver letters. It's a bit like our two-point and one-line work life.
Therefore, pigeons that can pass books have been strictly trained for a long time.
Extended data:
Flying pigeons spread books early, but they have disadvantages.
Flying pigeons, which are very common in costume dramas, originated very early. Around 3000 BC, Egyptians had learned to send letters with pigeons.
Our ancestors also began to use this method 2500 years ago. Carrier pigeons were once called "flying slaves" by them. When Zhang Qian and Ban Chao went to the Western Regions in the Han Dynasty, they brought a large wave of pigeons to the Western Regions to convey information to the current dynasty. Legend has it that when Emperor Gaozu Liu Bang was besieged by Chu overlord Xiang Yu, he also used flying pigeons to send books to attract reinforcements to escape.
In the Tang dynasty, there were also homing pigeons specially used for military purposes. In post offices, border crossings, government agencies, hotels, capitals and important towns, there are pigeon departments dedicated to transmitting information. In the war between Xixia and Northern Song Dynasty, Xixia army also used homing pigeons for military communication. It can be said that in ancient times, homing pigeons played a very important role, more important than today's police dogs and rescue dogs.
However, the biggest disadvantage of flying pigeon book transmission is instability, which can not guarantee that the information can be conveyed in place. It may have been cut off by the enemy just after flying into the air; It is also possible to fly in the sky and become an eagle's belly meal, or stop to find a food and become a roasted pigeon.
And flying pigeons can only deliver books in one direction. For example, if you send a message from Luoyang to Hangzhou, you must first bring the homing pigeons from Luoyang to Hangzhou. After flying, homing pigeons will only fly from Hangzhou to Luoyang. If it wants to take the news to Tibet, it will get lost.
References:
Baidu encyclopedia-flying pigeon biography