Micro Air Vehicles (MAVs) have a long history in science fiction; read some examples and then look at the MAV video produced by General Dynamics for the Air Force Research Laboratory.
...the Scarab buzzed into the great workroom as any intruding insect might, and sought the security of a shadowed corner. There it studied its surroundings, transmitting to its manipulator, far away now, all that it heard through its ear microphones and saw with its minute vision tubes. (More about Scarab flying insect robot from The Scarab by Raymond Z. Gallun )
On the chest of drawers something was perched. Something that gleamed, shiny metal, gleamed and clicked as it turned toward her. She saw into two glassy mechanical lenses, something with a tubelike body, the size of a child's bat, shot upward and swept toward her. (More about robot tracking devices from Vulcan's Hammer by Philp K. Dick )
Gersen continued, "There is a stick-tight watching us, although I have not yet located it. Its microphone probably registers our conversation... (See variations of stick-tights from The Star king by Jack Vance )
The dark birdforms dotted the mountaintops like statues of prehistoric beasts, wings outspread. Had there been an eye to observe them, it might not even have noted their minute, tropism-like pursuit of the sun across the sky as they recharged their batteries for the night's flight... (More about tracer-birds from Changeling by Roger Zelazny )
Blurbflies are allowd to travel the streets, buzzing their adverts alive and direct to the punters.
Blurbs shall stand for Bio-Logical-Ultra-Robotic-Broadcasting-System.
Only the company shall manufacture the blurbs. Other businesses or individuals may purchase blurbs from the Company, pre-loaded with messages and armed to the teeth, for the appropriate price. (Read more about blurbflies from Nymphomation by Jeff Noon )
(Micro air vehicle video from Air Force Research Laboratory)