How Strong Are Termite Mounds?
WouterTermite mounds are the result of insects excavating underground tunnels to create an intricate ventilation system. Some of these structures are as high as ten times stronger than the soil that surrounds them. They are also a source of food and shelter for many animals. Some of them can remain intact for hundreds of years.
A research team at the Harvard School of Engineering and Applied Sciences investigated how strong are termite mounds. The study used a variety of measurements. They measured the amount of CO2 in the mounds, external winds, and temperatures in various parts of the mounds. The researchers also performed behavioral tests. They found that the number of aggressive interactions at the mound level was not a factor in the pattern of the mounds.
The researchers found that a large amount of fine particles increases the attractive van der Waals forces. This is expected to facilitate greater consolidation of the soil. Moreover, the higher the polydispersity of the particles, the better the packing configuration.
Researchers believe that termites are building a long-term structure. In addition to its strength, it can also help other wildlife to reach food sources. In the process, it also helps to keep the temperature inside the nest constant.
Termite mounds are constructed using boluses of different sizes packed together. The boluses are then dried under room conditions. When the boluses are re-wetted, they break down and form aggregates that disintegrate. Eventually, the boluses form a cohesive force, known as soil suction.
