The drones have a type of artificial intelligence that detects nearby craft and fires on them until the ship is disabled (hence their name). They can differentiate between other drones and ships so they do not end up fighting each other. Their hull is quite weak and sufficient weapons fire can destroy them quite easily without giving them time to react. The technology was first encountered by Major Samantha Carter in 2003 when she accompanied Warrick Finn in the loop of Kon Garat. They were able to navigate through the drone field without taking much damage to the Sebrus, but the Tritan was not as lucky and was disabled quite early in the race. (SG1: "Space Race")