"And the Lord shall utter His voice before His army: for His camp is very great".(Joel ii. 2-11).
Nothing can be more vividly accurate than this splendid description of the Locust armies. First we have the darkness caused by them as they fly like black clouds between the sun and the earth. Then comes the contrast between the blooming and fertile aspect of the land before they settle on it, and its utter desolation when they leave it. Then the poet-prophet alludes to the rushing noise of their flight, which he compares to the sound of chariots upon the mountains, and to the compact masses in which they pass over the ground like soldiers on the march. The impossibility of checking them is shown in verse 8, and their climbing the walls of houses and entering the chambers in verse 9.
There is one passage in the Scriptures which at first sight seems rather obscure, but is clear enough when we understand the character of the insect to which it refers: "I am gone like the shadow when it declineth: I am tossed up and down as the locust" (Ps. cix. 23).
Although the Locusts have sufficient strength of flight to remain on the wing for a considerable period, and to pass over great distances, they have little or no command over the direction of their flight, and always travel with the wind, just as has been mentioned regarding the quail. So entirely are they at the mercy of the wind, that if a sudden gust arises the Locusts are tossed about in the most helpless manner; and if they should happen to come across one of the circular air-currents that are so frequently found in the countries which they inhabit, they are whirled round and round without the least power of extricating themselves.
The course then of the Locust-swarms depends entirely on the direction of the wind. They are brought by the wind, and they are taken away by the wind, as is mentioned in the sacred narrative. In the account of the great plague of Locusts, the wind is mentioned as the proximate cause both of their arrival and their departure. See, for example, Exod. x. 12, 13:
"And the Lord said unto Moses, Stretch out thine hand over the land of Egypt for the locusts, that they may come up upon the land of Egypt, and eat every herb of the land, even all that the hail hath left.
"And Moses stretched forth his rod over the land of Egypt, and the Lord brought an east wind upon the land all that day, and all that night; and when it was morning, the east wind brought the locusts."
Afterwards, when Moses was brought before Pharaoh, and entreated to remove the plague which had been brought upon the land, the west wind was employed to take the Locusts away, just as the east wind had brought them.
"He went out from Pharaoh, and entreated the Lord.
"And the Lord turned a mighty strong west wind, which took away the locusts, and cast them into the Red Sea; there remained not one locust in all the coasts of Egypt" (Exod. x. 18, 19).