Book excerpt: Influential American architect Philip Johnson once mused, "All architecture is shelter; all great architecture is the design of space that contains, cuddles, exalts, or stimulates the persons in that space." But with just a small swap of a key word, Johnson could well have been describing animal nests. Birds and insects are nature's premier architects, using a dizzying array of talents to build functional homes in which to live, reproduce, and care for their young. Recycling sticks, branches, grass, and mud to construct their shelters, they are undoubtedly the originators of "green architecture." A visual celebration of these natural feats of engineering and ingenuity, Architecture by Birds and Insects allows readers a peek inside a wide range of nests, offering a rare opportunity to get a sense of the materials and methods used to build them. Here, we see the kinds of places where nests are built--for instance, the house wren has been known to occupy cow skulls, flower pots, tin cans, and the pockets of hanging laundry, while the uglynest caterpillar prefers rose bushes and cherry trees. Inspired by the vast nest collection at the Field Museum, which features specimens gathered throughout North and South America, Peggy Macnamara's paintings are enhanced by text written by museum curators. This narrative provides a foundation in natural history for each painting, as well as fascinating anecdotes about the nests and their builders. Like so many natural treasures, nests are easy to ignore. But Macnamara's gorgeous paintings will undoubtedly change that. Architecture by Birds and Insects at last gives the tiniest engineers their rightful moment in the spotlight, and in so doing increases awareness and encourages the protection of birds, insects, and their habitats. Readers will never look at a Frank Gehry design, or a treetop nest, the same way again.