My bike airtag is out of range of my iPhone much of the time due to it being out in the garage. I’ve not heard it beeping at all other then when moving the bike to get at something.
The AirTags don't beep when left at home. However, if the AirTag "thinks" it has been moved it goes off after a random number of hours. This may be the case if they connect to a passing iPhone which doesn't have a very precise location at that moment or if the accelerometer detects a motion because a coworker bumped the table where the AirTag was.
Worst part is that if you want to use an AirTag for stalking it’s super easy to remove the speaker as it’s only magnetically attached to the circuitry.
All of this mess for honest customers just for a hypothetical stalker obsessed enough to use an AirTag but also lazy enough to not disable the speaker.