These Termite Mounds Are 4,000 Years Old — And Still In Use

Two hundred million mounds of dirt dot an area about the size of Great Britain in a tropical forest in northeastern Brazil. The cone-shaped dirt piles are roughly twice as tall as the average American man and stretch 30 feet across at the base. The mounds, the work of countless generations of termites, rise from the earth every 65 feet or so and are visible from space.