Take, for instance, the lovely hammock-like basket, hung by its rim beneath the fork of some low branch, which is made by the little grey, red-eyed vireo, which carols to us all the early summer days from every garden and orchard. Such a nest was hung in a maple close to my porch. The bird had built it within arm's length of where we were constantly passing, yet we never saw it until it was quite finished; and the only way we could get a look at it then was by pulling aside a branch. This care was not taken from fear of us, but in the hope that the cradle would escape the sharp eyes of red squirrels, weasels, bluejays, and other creatures who hunt for and rob birds' nests of eggs and young to get food for themselves. I am happy to say, however, that the vireo's nest was not disturbed. How to hide their nests safely is the great question in the minds of all the little birds. The big, strong ones do not need to worry about that so much, because they can drive away most robbers; therefore, we find that the hawks and crows, jays, kingbirds, and others able to take care of themselves, usually set their baskets in the crotch of some tree, where they can be seen easily enough, but all nests of this kind are strongly made, and fastened so that the winds shall not rock them out of their places or spill the contents. But the _little_ birds try to hide their homes in various clever ways. A good many seek holes and crannies. The woodpeckers are able to dig these for themselves, for their beaks are like chisels. Others, like the wrens, bluebirds, nuthatches, chicadees, and so forth, find knot-holes, places where a branch has broken off, and various small hollows, in which to make their beds, where the young will be snug in bad weather, and pretty safe from all enemies except snakes. Others, like the kingfisher, the sand-swallow, and certain sea-birds, make or find holes in earth-banks and rocky cliffs, so that their babies are born in a tiny cave. All of our swallows, before the country was settled by white people, lived in this manner or in hollow trees; but as soon as civilization came those we soon named barn-swallows left the wilds and put their nests under the roofs of barns and other outbuildings. Then some one, remembering the ways of old England, began to put bird-houses in the gardens; and now, in all parts of the United States, you may find those cousins of the swallows, the purple martins, living by the dozen in these lofty little hotels on the top of a pole.