Best considered a kind of airborne infantry, these flying insectile warriors occupy an unusual stratum in the Covenant hierarchy. Drones do not interact with other species except to trade and serve in a military capacity. Their ability to fight on the wing makes them an excellent strategic weapon against ground-based, largely bipedal opponents.

NOTE: This sounds more like an apology for how Drones have been implemented than anything else: they seem to operate entirely outside the troop hierarchy. They aren't affected by morale, don't cooperate with other units in groups. They're basically waves of enemies separate from other kinds of encounters, even when they occur in close proximity. At least they don't have snipers.