This book takes a look at 'animal architecture' from several different perspectives. One of these is how animals as builders have altered the environment, from earthworms making soil, tunnels providing microhabitats for other organisms, and culminating in humans as the ultimate environment-changers. It also looks at how some species build by instinct, without needing intelligence; how social organisms (such as termites or ants) decide where to build a nest; how nest and other structures evolve over time; how animals build traps, tools and bowers.