A drone is an aerial technology used by A.L.I.E.. She owned a large fleet of small drones which she used for aerial reconnaissance and security.
In Bodyguard of Lies, Murphy, Jaha, Craig, and Richards discover a massive solar panel field in the Dead Zone and comes across a drone, which begins taking off across the shore of a sea. The group decides to follow it.
In Blood Must Have Blood (Part 2), after reaching A.L.I.E.'s Island and leaving Murphy behind, at the lighthouse, Jaha decides to follow it. Later, while chasing after a drone, Jaha encounters a group of drones surrounding a well-kept mansion.
In Wanheda (Part 1), after being trapped in a bunker at the lighthouse for 86 days, Murphy manages to escape, before encountering a drone. After chasing a drone, Murphy sees many drones flying around a well-kept mansion. In Wanheda (Part 2), Emori mentions about the drone to Murphy.
In A Lie Guarded, Abby's team – consisting of her, Jackson, Raven, Murphy, Emori, Nyko, Luna, Miller, and three Ark Guards – arrive to Becca's Island. When they cross a line of obelisks, they are attacked by armed drones. The drones kill Nyko and a guard, before Miller is able to shoot one down. Using the downed drone, Raven is able to deactivate the entire fleet.
In The Tinder Box, Raven asked the computer in Becca's lab to show her the drone fleet's radiation detection software.
In Praimfaya, Raven and the others are watching the deathwave go past Polis through a drone's camera. She also mentions that according to the last drone, the wave is accelerating.