There are ten Hebrew words used in Scripture to signify locust. In the New Testament locusts are mentioned as forming part of the food of John the Baptist (Matt. 3:4; Mark 1:6). By the Mosaic law they were reckoned "clean," so that he could lawfully eat them. The name also occurs in Rev. 9:3, 7, in allusion to this Oriental devastating insect.

Locusts belong to the class of Orthoptera, i.e., straight-winged. They are of many species. The ordinary Syrian locust resembles the grasshopper, but is larger and more destructive. "The legs and thighs of these insects are so powerful that they can leap to a height of two hundred times the length of their bodies. When so raised they spread their wings and fly so close together as to appear like one compact moving mass." Locusts are prepared as food in various ways. Sometimes they are pounded, and then mixed with flour and water, and baked into cakes; "sometimes boiled, roasted, or stewed in butter, and then eaten." They were eaten in a preserved state by the ancient Assyrians.

The devastations they make in Eastern lands are often very appalling. The invasions of locusts are the heaviest calamites that can befall a country. "Their numbers exceed computation: the hebrews called them 'the countless,' and the Arabs knew them as 'the darkeners of the sun.' Unable to guide their own flight, though capable of crossing large spaces, they are at the mercy of the wind, which bears them as blind instruments of Providence to the doomed region given over to them for the time. Innumerable as the drops of water or the sands of the seashore, their flight obscures the sun and casts a thick shadow on the earth (Ex. 10:15; Judg. 6:5; 7:12; Jer. 46:23; Joel 2:10). It seems indeed as if a great aerial mountain, many miles in breadth, were advancing with a slow, unresting progress. Woe to the countries beneath them if the wind fall and let them alight! They descend unnumbered as flakes of snow and hide the ground. It may be 'like the garden of Eden before them, but behind them is a desolate wilderness. At their approach the people are in anguish; all faces lose their colour' (Joel 2:6). No walls can stop them; no ditches arrest them; fires kindled in their path are forthwith extinguished by the myriads of their dead, and the countless armies march on (Joel 2:8, 9). If a door or a window be open, they enter and destroy everything of wood in the house. Every terrace, court, and inner chamber is filled with them in a moment. Such an awful visitation swept over Egypt (Ex. 10:1-19), consuming before it every green thing, and stripping the trees, till the land was bared of all signs of vegetation. A strong north-west wind from the Mediterranean swept the locusts into the Red Sea.", Geikie's Hours, etc., ii., 149.