"I often watched him, too, when he was drinking. As he was so crippled, I used to pour a few drops of water on the floor of his cage, and when he felt thirsty he would scoop up a little in his lower jaw, and then throw his head back in order to let it run down his throat. But in a state of freedom bats drink by just dipping the lower jaw into the water as they skim along close to the surface of a pond or a stream, and you may often see them doing so on a warm summer's evening."
The pipistrelle, a common European bat, is said to feed chiefly upon gnats, of which it must devour a very large number, and as it much prefers to live near human habitations, there can be no doubt that it helps to keep houses free from these disagreeable insects. In captivity it will feed freely upon raw meat chopped very small. It appears earlier in the spring than the other bats, and remains later in the autumn.
These bats of the Old World have a most curious leaf-like membrane upon the face, which gives them a very odd appearance. In the great horseshoe bat this membrane is double, like one leaf placed above another. The lower one springs from just below the nostrils, and spreads outward and upward on either side, so that it is shaped very much like a horseshoe, while the upper one is pointed and stands upright, so as partly to cover the forehead. The ears, too, are very large, and are ribbed crosswise from the base to the tips; so that altogether this bat is a strange-looking creature.
Perhaps none of the bats is more seldom seen than this, for it cannot bear the light at all, and never comes out from its retreat until darkness has quite set in. And one very seldom finds it asleep during the day, for it almost always hides in dark and gloomy caverns, which are hardly ever entered by any human being. In France, however, there are certain caves in which great numbers of these bats congregate together for their long winter sleep. As many as a hundred and eighty of them have been counted in a single colony. And it is a very strange fact that all the male bats seem to assemble in one colony, and all the female bats in another.
In Central and South America, and also in the West Indian Islands, a number of bats are found which are known as vampires. Some of these eat insects, just like the bats of other countries, and one of them--known as the long-tongued vampire--has a most singular tongue, both very long and very slender, with a brush-like tip, so that it can be used for licking out insects from the flowers in which they are hiding. Then there are other vampires which eat fruit, like the flying foxes, about which we shall have something to tell you soon. But the best known of these bats, and certainly the strangest, are those which feed upon the blood of living animals.