When they become perfect insects and gain their wings, they proceed, as before, in vast myriads; but this time, they direct their course through the air, and not merely on land, so that not even the broadest river can stop them. They generally start as soon as the sun has dispelled the dews and warmed the air, which, in its nightly chill, paralyzes them, and renders them incapable of flight and almost unable even to walk. Toward evening they always descend, and perhaps in the daytime also; and wherever they alight, every green thing vanishes. The sound of their jaws cutting down the leaves and eating them can be heard at a great distance. They eat everything of a vegetable nature. Mr. Moffatt saw a whole field of maize consumed in two hours, and has seen them eat linen, flannel, and even tobacco. When they rise for another flight, the spot which they have left is as bare as if it were desert land, and not a vestige of any kind of verdure is to be seen upon it. A very excellent description of a flight of locusts is given by Mr. Cole, in his work on South Africa:-- “Next day was warm enough, but the wind was desperately high, and, much to my disgust, right in my face as I rode away on my journey. After travelling some ten miles, having swallowed several ounces of sand meanwhile, and been compelled occasionally to remove the sand-hills that were collecting in my eyes, I began to fall in with some locusts. At first they came on gradually and in small quantities, speckling the earth here and there, and voraciously devouring the herbage.