In building a nest, the mason-bee, in going to and fro, day after day, travels, on the average, about 275 miles; half the distance across the widest part of France. All in about five or six weeks, she does this. Then her work is over. She retires to some quiet place under the stones, and dies. As I said, she never sees the babies she has done so much for. [Illustration: SURFACE MOUNDS OF THE MASON-ANT There are mason-ants as well as mason-bees. This illustration shows the works thrown up by some mason-ants that Dr. McCook found in a garden path one morning in May.] And although they are so stoutly built, the houses of the mason-bees, like those "cloud-capped towers and gorgeous palaces" that Shakespere speaks of, finally go back to the dust. But while one of these little mothers is building a new home or repairing an old one left by a mother of the previous year, you would suppose the fate of the world hung on it; as indeed the fate of the world of mason-bees does. Scrape! Scrape! Scrape! With the tips of those little jaws, her mandibles, she makes the stony dust. Rake! Rake! Rake! With her front feet she gathers and mixes it with the saliva from her mouth. How eager and excited she gets, how wrapped up in her work as she digs away in the hard-packed mass in the tracks of the roadway! Passing horses and oxen, and the French peasants with their wooden shoes, are almost on her before she will budge. And even then she only flits aside until the danger has passed. Then down she drops and at it again! But sometimes, the boys and the teacher found, she starts to move too late--so absorbed is she, it would seem, in the thought of that tiny little home over there among the pebbles. Poor little lady! HIDE AND SEEK IN THE LIBRARY Perhaps nothing in nature is more wonderful than an insect; particularly when you consider that he _is_ only an insect! So, of course, whole libraries have been written about insects. Here are a few of the most interesting books dealing with the subject: Beard's "Boy's Book of Bugs, Butterflies and Beetles"; Comstock's "Ways of the Six-Footed"; Crading's "Our Insect Friends and Foes"; Doubleday's "Nature's Garden"; Du Puy's "Trading Bugs with the Nations." This about trading bugs is an article in "Uncle Sam: Wonder Worker," and tells how Uncle Sam "swaps" with other nations to get rid of injurious insects and bring in useful ones. Grant Allen's "Sextons and Scavengers" ("Nature's Work Shop") tells many curious things about the sexton beetles; how, by tasting bad, they keep birds and things from eating them; why you will always find an even number--never an _odd_ number--of sextons at work together; what they use for spades in their digging; why male sextons bury their wives alive, and why there is reason to believe that these weird little insects have a sense of beauty and of music.