Drones have become a ubiquitous part of the war in Ukraine. Both sides use consumer quadcopters to track the enemy and drop grenades. Russia has used Iranian Shahed-136 drones to torment Ukrainian cities. In February Russia detected Ukranian drones deep in its territory. More recently Ukraine has been converting devices designed for the sport of drone-racing into small loitering munitions. Last year its forces released a video of a racing drone diving through an open doorway into a building occupied by Russian troops and exploding. A Ukrainian military drone team called Angry Birds claims to carry out half a dozen racing-drone attacks a day. How important could these improvised weapons become?