At this question Emile put on his thinking-cap, closing his eyes and rubbing his forehead; but no ideas came. Nor were Jules and Louis any prompter with an answer. “Nobody knows? Well, then, so much the better, for you will have the satisfaction of finding it out for yourselves, from the shape of the teeth. The incisors, small and weak, which you see on an enlarged scale in this picture of a bat’s set of teeth—do they look as if they were made for gnawing vegetable substances, after the manner of rats and rabbits? Could they cut any such tough fodder?” “Certainly not,” replied Jules; “they are too weak to be of much use. And then it seems to me those two sharp, curved fangs must belong to a flesh-eating animal.” “The long, pointed canines do indicate as much, but the molars show it perhaps still more plainly. With their strong and sharp indented crowns fitting so well into the sharp-edged depressions of the opposite jaw—are those molars designed to crush grain, to grind, slowly and patiently, fibrous substances?” “No,” said Jules; “they are the teeth of a flesh-eater, not the grist-mill of an herbivorous animal.” “I am sure now,” affirmed Louis, “that the bat lives on prey.” “It is a greedy hunter of flesh and blood,” Emile declared. “The cat’s teeth are not more savage-looking.” “All that is quite correct,” said Uncle Paul. “The teeth have taught you the chief thing about the animal’s habits. Yes, the bat is a hunter, an eater of live prey, a little ogre always demanding fresh meat. It only remains to find out the kind of game it likes. Evidently the size of the prey must suit the size of the hunter. A bat’s head is no bigger than a large hazelnut. It is true the mouth is split from ear to ear and can, when wide open, swallow mouthfuls larger than the smallness of the animal would lead one to suppose. Nevertheless the bat can attack only small creatures. What can it be that it goes chasing through the air when, after sunset, it flies hither and thither unceasingly?” “Gnats, perhaps, and night-moths,” Jules suggested. “Exactly. Those are its prey. The bat lives on insects exclusively. All are food for its maw: hard-winged beetles, slender mosquitoes, plump moths, flying insects of all sorts; in fact, all the little winged foes of our cereals, vines, fruit-trees, woolen stuffs—all those creatures of the air that come in the evening, attracted by our lighted rooms, and singe their wings in the flames of our lamps. Who would undertake to say how many insects bats destroy when they fly around a house? The game is so small, and the hunter is so hungry.