From bird nests and beaver dams to spider webs and the display arenas of bowerbirds, the architecture of animals has fascinated our species from the dawn of history. The order and regularity of honey bee comb has inspired human builders and philosophers alike. Paper-making wasps and adobe-using birds may have opened our eyes to important technological innovations, and the relentless works of coral colonies dwarf human achievements. How do animals manage their feats of engineering, and what does it tell us about their minds?