As one listens to their friendly song it is hard to appreciate what fighters they are among themselves, the larger ones even turning cannibals when food is scarce, although a glance at the photograph shows how well equipped they are for battle. Their great black eyes, only shinier black than their coal-black armored necks, their jointed palpi with which they feed themselves, their thick, leathery wings pressed against their sides like a box cover, and their strong, muscular, spiny hind legs, with which they jump a hundred times their own length, do none of them contribute to beauty, though quite in keeping with their armored war-horse appearance. Two long, flexible circi protrude like tails behind, but the task of finding out what they are for has been too difficult for man. Perhaps the strange nerve-ending hairs which they bristle with may be sensitive to vibrations of the air, of which we yet know nothing. [Illustration] THE GROUND CRICKET Unlike its jet black relative of the fireside, the striped ground cricket forages by day on grassy slopes. It is a more omnivorous scavenger than the hyena, for it eats decaying plants as well as animals. Its big brown eyes, which cover half its head, see, doubtless, many ways at once, and its long, whiplike antennæ, which it waves constantly as it springs through the grass, are believed to scent odors which are inconceivably faint, such as the odor of a blade of grass, a pebble, or a decaying leaf. [Illustration] THE STONE OR CAMEL CRICKET (_Ceuthophilus uhleri_, Scudd.) It would not be a good idea to let the children think that creatures such as this were prowling round the house at night--that is, unless you assure them that it is only a harmless, tawny yellow stone-cricket from the shady woods, where it generally hides under stones and damp, decaying logs. It seems strangely equipped for its night life, for it has antennæ as long as its body. I cannot help wondering if these help it to jump in the dark. Fabre, the great French entomologist, has tried, as others have, to find out just how the insects use their antennæ and what they are really for. He says at last, "our senses do not represent all the ways by which the animal puts himself in touch with that which is not himself; there are other ways of doing it, perhaps many, not even remotely analogous to those which we ourselves possess." [Illustration] A MONSTER OF THE UNDERWORLD: THE MOLE CRICKET (_Gryllotalpa borealis_, Burm.) The creatures of the air which hide away their eggs that their larvæ may hatch out underneath the ground must reckon with this burrowing beast.