So drones might be one thing, but how about a government controlled, 1.2 inch spy device that can fly into your open door or window?
RoboBee is a tiny robot capable of flight. The culmination of twelve years of research, RoboBee solves two key technical challenges of micro-robotics. Engineers invented a process inspired by pop-up books that allowed them to build on a submillimeter scale precisely and efficiently. To achieve flight, they created artificial muscles capable of making the wings beat 120 times per second.
The goal of the RoboBee project is to make a fully autonomous swarm of flying robots for applications such as search and rescue and artificial pollination. For that to be feasible, researchers will have to figure out how to get power supply and decision making functions, which are currently handled via a tiny tether to the robot, on board.
It is believed that the 3 cm (1.2 in) wingspan of RoboBee makes it the smallest man-made device to achieve flight.
https://en.wikipedia.org/wiki/RoboBee
