> AirTags will beep if they are away from their owner's iPhone - at a random time between eight and 24 hours

However, it's possible to damage the speaker, so it becomes silent, without damaging the AirTag itself.

That's not great if someone steals your backpack and finds out you're tracking it.

They actually do start an audible alarm after being separated from their owner, starting sometime between 8 and 24h after separation. I don’t know the interval though.