How to use AirTags to keep track of dogs?

I have multiple dogs and multiple sizes in multiple family units. They’re all relatives of each other as we are. They mean the world to us from the Chihuahuas to the English Bulldogs and back again but sometimes they wander and they get out AirTag work if it’s placed onto a existing collar and please tell me how it works specifically I’m not very good at this stuff and I don’t wanna waste money or time and I don’t want my family to think that I’m doing something that is futile, thank you need to have decent idea of how this works from A Lehman’s terms

[Re-Titled by Moderator]