A moving AirTag will start chirping was little as a few hours after not being near it’s paired device - which alerts the thief, unfortunately. But, AirTags use

A moving AirTag will start chirping was little as a few hours after not being near it’s paired device - which alerts the thief, unfortunately. But, AirTags use a proper speaker rather than a piezo one - so it is possible to remove the permanent magnet and make them silent. (See YouTube for details) If you were worried about a high value item (eg a motorcycle) you could hide two - a sacrificial regular one, and a better hidden silenced tag that should remain undetected for at least a few days.