This particular millimeter-sized drone was inspired by flies as well as other kinds of wings insects, as they are able to hover in the air for a prolonged period. Apart from that, this particular research group has the faith that such tiny drones could be used across a wide range of situations, including having a better understanding of the insect population as well as pollinating plants.
Something tells me that the military, too, would like to get hold of such drones. A tiny drone which is no larger than your average insect could come in handy in surveillance and espionage missions, don’t you think so? It can snoop around undetected, recording what is being said and done, before returning to base. Hopefully birds of prey would not mistake such drones as their next snack.