If one were to try to describe even half of the great number of different kinds of falcons and hawks in the world, or even in America, this book would not be large enough for the purpose. Among those most often seen in this country are two large, softly plumaged, brown hawks, with square, barred tails, of the group called buzzards. One is the red-tailed, another the red-shouldered, and a third the broad-winged, the several names denoting the specially noticeable features in each case. All make their homes in the woods, constructing big nests in trees, and early in the spring laying brown-blotched eggs. These hawks fly heavily over the fields in search of frogs, small snakes, field-mice (of which they catch great numbers), and once in a while seize a young bird which cannot yet fly very well; but mostly they live on mice and insects. The country people call all of them hen-hawks, and are likely to shoot them when they can; but in truth they harm the poultry-yard very little. The really dangerous "hen-hawks" are two or three much smaller and more active falcons, such as the Cooper's and sharp-shinned hawks. They are swift and fierce, and will dart down and snatch a bird from its perch or pick up a small chicken with amazing suddenness and speed. These hawks are sometimes called kestrels, after a well-known European falcon which they resemble. KESTRELS AND OTHER CHICKEN-HAWKS You may often see one or the other of these hovering high in the air, as do the English kestrels, about three or four hundred feet from the ground, and carefully watching for the mice upon which after all they mainly feed. It has eyes like telescopes, so that as soon as a mouse pokes its head out of its burrow it catches sight of it, swoops down upon it, seizes it in its talons, and carries it off to be devoured. The number of mice which it catches in this way is very large, and it has been estimated that at least ten thousand of these destructive little creatures are killed by every kestrel in the course of every year. So we must look upon the bird as one of the best friends of the farmer, in spite of the occasional loss of a chicken. When it cannot find any mice the kestrel will sometimes eat small birds, and now and then it will feed upon cockchafers and other large insects, catching them in its claws as they fly, and then passing them up to its beak. Kestrels sometimes build in trees and sometimes in towers and old buildings. But very often they make use of the deserted nest of a magpie or a crow. From four to six eggs are laid, which are blotched with reddish brown on a bluish-white ground.