Man, you guys are destroying the simplicity of the Rev.9 chapter and its symbols.
The locusts of Rev.9 are not literal monsters; they are certain men. God first covered this idea through His OT prophet Joel. The locust army represents "a nation", a certain people that will strip the wealth of God's people in the last days using... what comes out of their mouths.
Joel 1:1-3
1:1 The word of the LORD that came to Joel the son of Pethuel.
2 Hear this, ye old men, and give ear, all ye inhabitants of the land. Hath this been in your days, or even in the days of your fathers?
3 Tell ye your children of it, and let your children tell their children, and their children another generation.
KJV
God's servants were to stay on the lookout for this event, and tell it to their children, and their children's children until the generation comes that will see it.
Joel 1:4-11
4 That which the palmerworm hath left hath the locust eaten; and that which the locust hath left hath the cankerworm eaten; and that which the cankerworm hath left hath the caterpiller eaten.
5 Awake, ye drunkards, and weep; and howl, all ye drinkers of wine, because of the new wine; for it is cut off from your mouth.
6 For a nation is come up upon my land, strong, and without number, whose teeth are the teeth of a lion, and he hath the cheek teeth of a great lion.
7 He hath laid my vine waste, and barked my fig tree: he hath made it clean bare, and cast it away; the branches thereof are made white.
8 Lament like a virgin girded with sackcloth for the husband of her youth.
9 The meat offering and the drink offering is cut off from the house of the LORD; the priests, the LORD's ministers, mourn.
10 The field is wasted, the land mourneth; for the corn is wasted: the new wine is dried up, the oil languisheth.
11 Be ye ashamed, O ye husbandmen; howl, O ye vinedressers, for the wheat and for the barley; because the harvest of the field is perished.
KJV
The meaning is the locust army will be very thorough, each stage continuing to eat up what the previous one left. The harvest of the field, the corn, the new wine and oil being wasted by them is symbolic of their takeover of the wealth of God's people in the last days. These are not 'real' locust insects, they are men, God is only using the locusts as a metaphor for how they will work upon the earth in the last days.
Joel 2:3-9
3 A fire devoureth before them; and behind them a flame burneth: the land is as the garden of Eden before them, and behind them a desolate wilderness; yea, and nothing shall escape them.
4 The appearance of them is as the appearance of horses; and as horsemen, so shall they run.
5 Like the noise of chariots on the tops of mountains shall they leap, like the noise of a flame of fire that devoureth the stubble, as a strong people set in battle array.
6 Before their face the people shall be much pained: all faces shall gather blackness.
7 They shall run like mighty men; they shall climb the wall like men of war; and they shall march every one on his ways, and they shall not break their ranks:
8 Neither shall one thrust another; they shall walk every one in his path: and when they fall upon the sword, they shall not be wounded.
9 They shall run to and fro in the city; they shall run upon the wall, they shall climb up upon the houses; they shall enter in at the windows like a thief.
KJV
They act and work like an army, but it's not a literal army, because notice if they fall upon a sword they are NOT harmed. They enter into people's houses and windows "like a thief". Where did we hear that kind of metaphor before about the thief in the night and being a watchman so as to not allow our house to be broken up? (Matt.24).
In final, God says He will restore to His people what this great locust army destroyed, and He calls them "My great army which I sent among you":
Joel 2:25
25 And I will restore to you the years that the locust hath eaten, the cankerworm, and the caterpiller, and the palmerworm, My great army which I sent among you.
KJV