Most of these birds work for us the whole time, as do the owls. For they eat the same destructive animals, and they eat an enormous number. Yet we have a foolish prejudice against them, because two or three of them sometimes take poultry and game birds. Even when these birds do take our poultry and game birds, some good is done. For they naturally catch the weak ones who are not able to get out of their way. And it is better for the whole race of these birds that the weak ones should not live. It leaves the rest stronger, and better able to make their way in the world. This family is found all over the world. It includes birds of all sizes, from one as small as a sparrow to one who spreads his wings ten feet. In our country we have neither the smallest nor the largest. Of those you are likely to see, the least is the American Sparrow Hawk, who is not much larger than a robin, and the greatest is the Bald Eagle, who is sometimes a yard from the tip of his beak to the end of his tail. Hawks have wonderful eyes like a telescope and microscope in one, as I have told you in "The First Book of Birds." In eating without knife and fork, they often swallow food whole and throw up castings like the owls. In catching their prey these birds use their feet instead of their beaks. Even those who hunt grasshoppers and crickets seize them in their claws. Their feet are quite as useful as hands. In them they carry material for the nest as well as food for the little ones. The claws are powerful weapons of war, too. A hawk who is ready to fight throws himself on his back and presents his claws to the enemy. Few people would like to be grappled by those terrible claws. Hawks and eagles have wonderful wing power. Some of them can stay far up in the air an hour at a time. They go up in great circles with wings held stiffly out and not beating, till out of sight. Men have not yet been able to see quite how it is done. It is probably by using the wings as sailors use their sails, and making the wind carry them. The one of this family I shall tell you about is the FISH HAWK, or AMERICAN OSPREY, because he is found all over the United States. He is one of those which you will be most likely to see, and want to know about. The osprey is a large bird, about two feet long. He is dressed in chocolate brown, with white breast and white tips to many of his feathers. His head feathers are long, and lie back on his neck, giving a peculiar shape to the head, by which you may know him at once. These feathers too are white, so that as he flies over he looks as if he were bald. He has feet marvelously fitted to hold slippery fish. The talons are sharp, and the toes long, and rough on the under side, so that nothing can get away from them.