Yes, that seems strange to you, but you remember how ears are ears, and serve to hear with, no matter where on the body of the creature they are located. So blood is blood, and serves the purpose of blood, no matter what its color. The blood of some insects has a very bad odor, and in the case of certain beetles, when they are disturbed, this foul-smelling liquid oozes out of the joints of the legs. Yes, Mabel, it is probably used, like the "molasses" of other little friends we know, to repel enemies. But to return to breathing. Some larvae breathe by gills, and do not have spiracles until they are grown up, but all grown-up insects breathe by spiracles. Yes, John, the larvae of the dragon flies and May flies breathe with gills. I thought you would remember that. The water boatman breathes by spiracles, and carries his supply of air with him. All grown-up bugs breathe by spiracles. Now look down into the pond. I think you will see some water boatmen anchored near the bottom. Yes, May, they cling by their front feet. Their hind pair of legs are rather odd-looking; they have a fringe of hairs on the inside. John says their hind legs are modified to swim with. Very good, John. The hind legs are the oars that row these little boats about in the water. But why are the little boats that have come to anchor down there moving their paddles so constantly? Ah, yes; it is because they want fresh air to breathe. You know there is always air in pond water, and they keep their paddles moving, so as to change the envelope of air that surrounds them. [Illustration] They know what to do to take care of themselves, if they _are_ nothing but little bugs. When winter comes, they go down to the bottom of the pond and bury themselves in the mud. They lie there without moving or breathing until spring, when out they come, as lively as ever. Yes, certain other animals pass the winter in this way; the bears, for instance, find a snug den and sleep all through the coldest winter weather. We call this winter sleep of animals hibernation, and many of the insects hibernate. Yes, Ned, hibernating animals can get on with very little air; they sometimes seem to need none at all, and they take no food. May wants to know what these queer water boatmen eat. They suck out the juices of other insects. They must lay their eggs in the water, little Nell thinks. And so they do, on water plants. Near the city of Mexico there are species that lay enormous quantities of eggs in the ponds, and what do you think? The Indians mix these eggs with meal, make them into cakes, and eat them. The Mexican bugs are gathered by the ton, too, and sent to England as food for cage birds, fish, and poultry. Little Nell thinks there must be a great many bugs in a ton. Indeed, there are, probably about twenty-five millions of them; so you can imagine Mexico is well supplied with water boatmen!