Researchers have found 200 million still-inhabited termite mounds that are almost 4,000 years old in the dried forests in northeastern Brazil. These mounds cover an area of more than 230,000 square kilometers - about the size of Laos - and can be easily seen from space using Google Earth.

These mounds are not nests, but the outcome of slow and persistent excavation by a massive underground network that has been built by a single species of termites for thousands of years. “The amount of soil excavated is over 10 cubic kilometers, equivalent to 4,000 great pyramids of Giza, and represents one of the biggest structures built by a single insect species”, according to the lead researcher Stephen Martin at the University of Salford in the UK.

Each one of these termite mounds consists of up to one million individuals, which means the population in the network can reach many billions.

Termites live in a highly organized society, better known as a colony, which operates according to their caste: Reproductives, workers and soldiers. Each mature termite colony typically has one reproductive pair known as the king and the queen, and they produce a pheromone that prevents the workers from becoming reproductive adults. Termite queens have the longest lifespan of any insect in the world—some species can live up to 50 years.

Since the termites feed on dead plants and love to dig out the soil, they are ecologically important in the nutrient and carbon cycling of the ecosystem which they are a part of. Scientists have observed an obvious decrease in termite activities in areas where deforestation occurs.

While many hundreds of termite species are considered as pests that can cause serious damage to buildings and crops, they are often used as food and traditional medicines in many cultures. The local tribes in Brazil's Amazon rainforest have a long history of consuming it as an important source of protein.

(Video edited by Zhong Jianli)