I dont really care who's in my shop, dont need to know what they look like....just want them gone before they get loaded up so I have an alarm system integrated into my air system that runs a locomotive horn inside the shop ...when someone trips that trip-rope tied to the air valve aint nobody stayin' in that building. No mater what time of day or night, if Im at home I will hear that horn very plainly ( my bedroom is not more than 100 ft from that horn when it goes off).
That's hilarious! Bet you don't have mice, or cats, or glass jars in there either!
I really should beef up my sound too. But I don't keep air in my tanks.