It would be difficult to think of anything more _rusé_ than this, within the limits of the animal kingdom; but certain beetles play a trick which is quite as ingenious, and perhaps even more remarkable. These are the bombardier beetles, as they are very appropriately called, little creatures not more than the third of an inch long, and with nothing very remarkable about their appearance. When, however, they are pursued by some larger beetle, or other insect, of carnivorous habits, all at once, just as they seem on the point of being overtaken, they fire off a gun, and the pursuer rolls head over heels. That, at least, is what it looks like. There is smoke and a sudden bang that one can just hear, and it seems as if the big beetle had been shot. What really happens is this: the bombardier beetle discharges from a gland in the posterior portion of the abdomen, with which it is furnished, a very acid fluid, which, by a chemical process, when it meets the air, volatilises into smoke, with a slight explosion. Whether it is the explosion or the acid properties of the fluid, or some disagreeable smell it has, which upsets the beetle that is in pursuit, I am not quite sure. If the latter, then the bombardier beetle is something like the skunk, an animal we shall have something to say about later on, but I think it is the actual explosion, which, though weaker, acts in the same way as an explosion of gunpowder does. Whatever may be the reason, the effect is very remarkable, and in this sudden discharge by the little beetle, with the consequent instantaneous collapse of its enemy, we see one of the most ingenious of Nature’s devices for protecting her little children against her big ones. To look at, it is perhaps the most wonderful of all, for it is just like real artillery—smoke, an explosion, and then over rolls somebody—a regular battlefield.