As long as they have a favourable wind, nothing stops the progress of the Locusts. They press forward just like the vast herds of antelopes that cover the plains of Africa, or the bisons that once blackened the prairies of America, and the progress of even the wingless young is as irresistible as that of the adult insects. Regiments of soldiers have in vain attempted to stop them. Trenches have been dug across their path, only to be filled up in a few minutes with the advancing hosts, over whose bodies the millions of survivors continued their march. When the trenches were filled with water, the result was the same; and even when fire was substituted for water, the flames were quenched by the masses of Locusts that fell into them. When they come to a tree, they climb up it in swarms, and devour every particle of foliage, not even sparing the bark of the smaller branches. They ascend the walls of houses that come in the line of their march, swarming in at the windows, and gnawing in their hunger the very woodwork of the furniture.
We shall now see how true to nature is the terrible prophecy of Joel. "A day of darkness and of gloominess, a day of clouds and of thick darkness, as the morning spread upon the mountains: a great people and a strong; there hath not been ever the like, neither shall be any more after it, even to the years of many generations.
LOCUSTS.
"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.
"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.
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.