Swallows wear no gay colors. Nearly all of them look black and white as they sail about in the air. But when you see them closely, you see they are glossy dark blue or green, sometimes with changeable colors, but all dark, on the back. The BARN SWALLOW has a dull reddish breast, and his back is rich blue, almost black. He has a deeply forked tail, and a row of white spots on the shorter tail feathers. When he spreads his tail, it is very beautiful. He is called barn swallow because he prefers a barn for a nesting-place. Up on the beams, close under the roof, the pair build their mud cradle. It is interesting to see them at work. When they have chosen a place, they go to some puddle in the road. They stand around it on their tiny feet, holding their wings straight up like a butterfly's. Then they take up some of the wet earth in their beaks, and work it around till it is made into a little pill. With this pill they fly to the place they have selected, and stick it on to the beam. Then they go back for more. So they go on, till they have built up the walls of the nest, an inch thick, and three or four inches high. Sometimes they put layers of fine grass in, but often they use nothing but mud. Then they line it with feathers which they pick up in the chicken yard. Some swallows build a platform beside the nest, where one of the pair can rest at night; and when the little ones get big enough to fill up the nest, both parents can sleep there. When the swallows are flying about low over the grass, looking as if they were at play, they are really catching tiny insects as they go. And when they have nestlings to feed, they collect a mouthful which they make up into a sort of little ball. Then they fly to the nest and feed it to one of the little ones. Thus they keep the air clear and free from insects, and they do not a bit of harm, for they never touch our fruit or vegetables. Barn swallows are social, and always go in flocks. They sing, too,--a sweet little song, but not very loud. It is charming to hear them in a barn when five or six of them sing together. But one may often hear the little song from a single bird flying over. They are friendly among themselves, and they like to alight on a roof and chatter away a long time. In one place where I was staying, they liked to gather on a piazza roof right under my window. They often woke me in the morning with their sweet little voices. One morning the sound was so near, it seemed as if they must be in the room, and I opened my eyes to see. There on the sill close to the screen was one of the pretty fellows. He was looking in at the open window, and evidently keeping watch of me. When I moved a little, he gave the alarm, and the whole party flew away.