system
Given the following post, respond as if you're commenting on Reddit:
human
Eli5: How did carrier pigeons work?

How did they know where to go? Are their abilities exaggerated in books and films? Do you need a specific pigeon to go to a specific person?
gpt
They are just like most coop pigeons. They remember where they are fed. You take a carrier pigeon from their coop to the mission, writes a letter and attaches it to the pigeon. The pigeon flys to it's food supply.

Media has definitely over-exaggerated their abilities. It's not liking the movies where people can send pigeons back and forth to each other, except for those that are returning to their home coop. So, technically, you could transport multiple birds from one coop to another base, and transfer that second base is pigeons to the first base. You could then send a limited number of messages back and forth until the pigeons all returned to their own coops.