This is it. The “fly” is soft disclosure of spy tech. It possibly has been around for a while. Small drone “markers” placed on individuals can be used to then target them with other weapons. It is similar to “lighting up” or “illuminating” a battlefield target with a non visible laser to allow a missile to hit it (on a small scale).

Tiny drones can also drop off payloads like poison, radioactive pellets, and gps trackers. Seems like sci-fi Mission Impossible bullshit, but it is not.