When, in the last century, men began to settle on the prairies of the far West, they met this plague; and between 1870 and 1880 the gardens and farms and young orchards of Kansas, Nebraska, and other western districts, were ruined again and again. The government sent out several of the wisest entomologists it could employ to study the insects, and they found that these destructive red-legged grasshoppers had their home in the dry foothills of the Rocky Mountains, especially toward the north. They learned a great deal about the habits of the insects, and reported that there seemed no remedy just at hand; but that the more the West was settled and cultivated, the more grass and other food would be provided for the grasshoppers, so that they would not have to make those wide flights, and the more the plowing of the land and burning of rubbish would destroy their eggs, so that gradually the pest would become less and less, until finally it would cease to be troublesome. This has turned out to be true, and already the fear of grasshoppers has departed. The same thing is taking place in Egypt and some other improving countries, which no longer suffer from the plague of locusts as they used to do. The wonderful walking-stick and the leaf-insects also belong to this order. They are so marvelously like the objects after which they are named that as long as they keep still it is almost impossible to see them. They seem to know this perfectly well, and will remain for hours together without moving, waiting for some unwary insect to come within reach, for they are among the insects of prey. They are found in all the warmer parts of the world. Equally curious, too, is the praying-mantis, which also is very much like a leaf. It has very long front legs, with a row of sharp teeth running along their inner margin, and when it is hungry it holds these limbs over its head, in very much the attitude of prayer. That is why it is called the praying-mantis. Then when an insect comes within reach it strikes at it, and seizes it between the upper and lower parts of these limbs, so that the long spike-like teeth enter its body and hold it in a grip from which there is no escape. These occur in various parts of the world, including the warmer parts of America. DRAGON-FLIES AND MAY-FLIES The dragon-flies belong to another division of the _Orthoptera_. You must know these insects very well by sight, with their long slender bodies and their broad gauzy wings; for they are common in almost all parts of the country, and you can hardly go for a ramble on a sunny day in summer or autumn without seeing them in numbers. There are a good many different kinds. Some have yellow bodies, some blue ones, and some red ones, and the loveliest of all perhaps are the graceful demoiselles, whose wings are rich metallic purple. You may sometimes see these beautiful insects flitting to and fro over streams and ditches.