The termite towers
Termites construct fortresses that may contain several tons of mud and contain several million inhabitants. Ventilation and temperature control are therefore critical for survival of these communities. Around the margins of these termitaria are tall, thin-walled chimneys. As the sun warms the walls of these chimneys air becomes hotter than the air inside of these nests, the air in the chimneys therefore rises and with it draws air from the termitaria. Since the chimney walls are thin and porous, oxygen from the outside diffuses in. This air rises to the top of the nest and re-oxygenates the colony. In very hot weather the workers descend in tunnels that go deep into the ground water, and carries back a crop full of water that wets the wall and lowers the temperature through evaporation.