A video of a fly is circulating again. This time they claim it shows polymer drone flies, used by the U.S. military. Last year the same video was circulated with a claim that it shows drone insects caught spying in Africa.

That is an actual fly called Cuterebra ruficrus. See the following screenshots via iNaturalist NZ.

Insect-sized drones do exist. However, they cannot move and act like real bugs – at least not yet. Making devices with flapping wings is very difficult.

Further reading:
– The stealthy little drones that fly like insects (BBC)
– Researchers introduce a new generation of tiny, agile drones (MIT)