Like other technology in "Snow Crash", Rat Things are powered by a nuclear isotope battery, which requires extensive cooling due to the massive amount of waste heat generated. The Rat Things are passively cooled by a system of heat sinks that are only effective when the Rat Thing runs fast enough to move ambient air across the fins. To prevent rapid overheating when stationary, they must remain in their hutches (effectively dog houses), where they are continuously sprayed by jets of refrigerant. Through running, Rat Things are capable of breaking the sound barrier (about 768 mph at sea level), although this is not typically permitted by Mr. Lee's Greater Hong Kong's "good neighbor" policies due to noise reasons. Because they must be either moving at high velocities or actively cooling in their hutches, Rat Things are rarely seen by human eyes and few people know what they look like.