Hey Bojack!
Hadn't heard of the insect sized robots. I have heard of the Apache helicopter theory started by Hal Lindsey. However, if we use the details of their description, it soon becomes clear that these things that resemble locusts are demonic beings. The first clue of this, is that an star/angel falls from heaven having the key to the shaft of the Abyss and opens it. And out of the shaft comes smoke like a furnace and out of the smoke comes these locusts. The Abyss is the same place that Satan and his angels are toing to be thrown into when the Lord returns to the earth to end the age. And the Abyss is also the same place that those demonic being collectively called 'Legion' begged Jesus not to cast them into. Therefore, we can conclude that this are not helicopters coming from an underground base.
Another characteristic is that their king is the angel of the Abyss who is called Abaddon/Apollyon which means destroyer. We can also conclude from their descriptions having hair like women's hair, teeth like lions teeth, faces like human faces, tails and stingers like scorpions and looking like horses prepared for battle, that these are not your garden variety locusts.
That fact that they come up out of the Abyss and that they have as king over them the angel of the Abyss definitely tells us that these are demonic beings which resemble locusts. Also, by the description of their wings which sound like horses and chariots rushing into battle, as well as the reference to havinv teeth like lions teeth, I would say that they are not going to be 6 inches in length, but bigger in size. My thinking here is that horses and chariots rushing into battle would be a very low pitch rumble, which would mean that their wings would have to be bigger than a common locust, which make a higher pitched sound.
In studying this 5th trumpet, I concluded that these things will be demonic beings coming up being released from the Abyss. In further support of this, it states that that are told not to harm the grass of the earth or any plant or tree, but only those who did not have the seal of God on their foreheads. Therefore, because they are able to take instruction it tells me that they are intelligent.
Just my observation