In the 6th trumpet of Revelation, locusts are loosed out of the bottomless pit. This is an important portrait of what happens during the Great Tribulation. These locusts are loosed to attack those people who do not have the seal of God. Therefore, this is an attack on unsaved humanity. Please consider viewing the below video to understand what locusts mean in the Bible. Or, please consider viewing the Revelation 8-10 study notes on this website.