“Having one day descended into the grottoes of Arci, I was surprised to find there a kind of earth of a singular nature. It formed a bed of blackish matter several feet thick, almost entirely composed of parts of the wings and feet of flies and moths, as if these insects had gathered here in immense numbers, coming together for the express purpose of dying and rotting in company. It was nothing but bats’ dung that had been accumulating for years.” “What a curious kind of soil, made up entirely of the remains of dead insects!” Jules exclaimed. “I will add that sometimes this soil of flies and moths at the bottom of old quarries and caves is abundant enough for the farmer to take account of it and use it as a rich fertilizer. It is called bats’ guano.” “To make such heaps of it, then,” remarked Louis, “bats must destroy insects by millions and millions.” “Five or six dozen flies or moths are hardly enough for a bat’s evening meal; if a few June-bugs should make their appearance, they would be eagerly snapped up. If the band of hunters is a large one, judge of the thousands of harmful insects destroyed in a single season. Next to the birds we have no more valiant helpers than bats; and so I beg you to be friendly to these creatures which, while we are asleep and perhaps dreaming of our rich crops of pears and apples, peaches and grapes and grain, proceed with their silent warfare against the enemies of our harvests, and every evening destroy by myriads moths, mosquitoes, beetles, bugs—in short, the greater part of the insect throng that always threatens us with starvation if we do not keep vigilant watch.” “I see now that the bat does us a good turn,” Emile admitted. “All the same, it is frightfully ugly; and, besides, they say if it touches you it will give you the itch.” “There are any number of other sayings about it that are just as foolish, my boy. One is that the bat pricks with its pointed teeth the she-goat’s udders so as to suck her blood and milk; another is that it gnaws the sausages and bacon hung under the chimney mantel; also, that its sudden entrance into a house means misfortune. I have heard persons cry out because a bat had accidentally grazed them with the tip of its wing; and I have seen others pale with terror because they had found one of the innocent creatures fastened by a claw to their bed curtains. “Here, as in many other things, my dear children, you must take into account the folly of mankind, which is more given to error than to truth. If you were old enough to understand me, I should add that wherever I find a general agreement that a thing is black I think it well to look into the matter and find out whether, on the contrary, it may not be white. We are so stuffed with false notions that very often the exact opposite of the common belief is the real truth. Do you ask for examples? There are plenty of them.