In summer, these birds feed mostly upon insects, which they find on the ground. They have an amusing way of being fair in their feeding. As they walk about in little social parties looking for food, those who come last in the string find the insects nearly all picked up before they get a chance. So they take this clever way of getting their turn at the good things. Every few minutes those in the rear rise and fly over the heads of their friends and alight just before them. So they have the first pick for a while. Then, in a few minutes, those left behind fly over their heads, and take the lead for a time. So, without any quarreling, each one has a fair chance with all the rest. Other birds have found out this way of playing fair. I have seen great blue herons three feet tall do the same thing. In winter, when insects are scarce, the blackbird turns to grain and the seeds of weeds. But it has been found that he does more good by the weeds he keeps down than harm by the grain he eats. Brewer's blackbird usually nests in trees, not very high. One time a naturalist going about in Arizona, where are few or no trees, found a curious thing,--a good many blackbird nests, a little settlement one might call it, on the ground, and all strung along close to the edge of a steep bank. At first he could not see why the birds had chosen to be on the edge of a precipice. Then he remembered that horses and cattle roamed over the country, and these animals are careful never to graze close to an edge which might crumble and give them a fall. He concluded that the birds had wit enough to know that. If their nests were out on the plains, they would be likely to be stepped on, but near the edge, they were safe from hoofs. The common call of Brewer's blackbird is a harsh "chack;" but in the spring he turns musical, and serenades his mate with what we must call songs, because songs are what he intends. They are droll enough to listen to, and not very sweet. This bird is about the size of a robin, with violet-colored head in the sunlight. His mate is slate-colored. Birds who live in a crowd learn to be fair in their treatment of one another. An interesting story is told of the way a flock of blackbirds go to bed at night. They come to the roosting-place in little parties from all the country around. One would suppose the first one to get there would choose his place to sleep, and let the last one take what was left. But no! as they arrive, they alight in some big old tree outside the roosting-place. When all are in, they fly up together, circle around for a while, then all settle at the same time in the place where they are to sleep. XXIII THE CROW FAMILY (_Corvidæ_)[17] THIS is a large family. Some of our most intelligent birds belong to it. There are first the crows, much larger than a robin and dressed in black. They have long, pointed wings, and tails square at the end. They live in a crowd, and walk on the ground.