Intelligence
When attacking, Drones primarily employ ambush tactics, and are almost never seen working in coordination with other Xenomorphs, even when inside the Hive, preferring instead to operate alone. They are shown to be intelligent and patient, employing stealth in their assaults, often seeking to blend in with their environment and waiting motionless for their prey to come within range before striking.[4] In the novelization of Alien, Ash theorizes that the Drone is at least as smart as a dog, and probably more so than a chimpanzee.[7] It seems possible that Drones may not require the leadership of a Queen to function at an intelligent level, unlike Warriors who seem to be primarily driven by the Queen's commands and basic instinctual impulses. Drones often operate as scouts, as one of their alternate names implies, and are capable of making independent decisions.
Additionally, it seems that intelligence and abilities can vary between Drones. As seen in Alien vs. Predator, the Xenomorph known as Grid was capable of single-handedly defeating two Predators through a combination of stealth strikes and traditional combat, an exceptional feat for a lone Alien. Grid also seemed to act as something of a leader amongst the other Drones when they broke the Queen free.