- "These Unmanned Aerial Vehicles can detect the virus at less than ten parts per million in open air."
- ―2nd Lt. Joel Brunner
Unmanned Aerial Vehicles (UAV) are deployed by the military in later stages as a means of detecting Alex Mercer. Resembling real-life Sikorsky Cypher UAVs, they move around New York (usually around bases and Strike Teams) constantly scanning for any sign of infection. UAVs can be taken out by Alex's Whipfist power or a guided Air Kick attack. While they do not immediately pick out Alex, the disguise meter can be seen rapidly increasing while in range of their sensors.
- Though they do not directly attack you, they can summon strike teams and blow your cover. They can and will follow you so be wary if the alert bar does not seem to lower over time.
- At later stages, they come in large numbers and are normally accompanied by helicopters, a lethal combination.
- The UAVs are based on the design of the Sikorsky Cypher.
- Upon colliding with a chopper, in which logic would dictate it would be destroyed, or a least severely damaged, it instead suffers no damage and will inflict severe damage on the chopper.
- In Prototype 2, UAV's make a return though they don't act as viral detectors and will simply follow the player when they enter an alert.