Security firm Praetorian outfitted a drone with custom hardware to learn how many connected devices are being used in Austin, TX.

Given the explosion of connected devices, also known as the Internet-of-things, it’s natural that people would want to know just how many such devices are out there.

But how do you go about figuring out just how many of these devices—like thermometers or light bulbs hooked to the Internet—are being used in a given city? The answer is apparently to enlist the services of a drone that can fly above the city proper and gather tons of data pertaining to the connected gadgets and appliances.

A team of researchers at security company Praetorian wanted to discover how many IOT-friendly devices were being used in Austin, TX, and found that the best way to do so would be to outfit a drone with the company’s custom built connected-device tracking appliance and have it fly over the city, Praetorian vice president of marketing Paul Jauregui told Fortune.