A dust devil forms when hot air near the ground rises quickly through a small pocket of cooler, low-pressure air above it. If conditions are just right, then the air may begin to rotate. As the air rapidly rises, the hot air is stretched vertically and because of angular momentum, the spinning gets much more intense. Because the hot air cools when it rises, it eventually goes down to the base and expands horizontally, while more hot air shoots up the column to replace the lost air. The air that is displaced falls to the ground around the dust devil, creating a balancing force. Thus, a dust devil is formed.