Insects may bug you, but plants thrive on them
Sometimes I am asked questions like, “What good are mosquitoes?” My granddaughter once asked me, “Why did God make leeches?” These kinds of questions really mean, “What good are they to me?”
In fact, many plants and animals are of no use to humans at all, unless you consider the complex maze of interactions and dependencies of which the living world consists. It is like a large, complicated structure made of an array of interlocking blocks and beams. One is never sure what will happen if you remove one element. But that seldom satisfies the questioner very much.
But recently I found out that termites, usually associated with destruction, have become useful in one part of the world for a surprising use: construction. To understand this we have to consider how termites live.
Termites are one of the groups of social insects. They live in colonies and their behavior, from birth to death, is rigidly preprogrammed. Like honey bees and ants, they have been successfully surviving for millions of years. While some termites may take up residence in our homes, many live in the wild.
In some parts of the world there are termite species that create huge underground colonies with tall mounds that can reach as high as 30 feet in the air. These mounds are actually just ventilation tubes, and if you were to break one open you would find no termites. The termites are several feet below ground.
Not only are the mounds dominant in the landscape, they are also a lasting features, as the annual monsoon rains do not seem to harm them or wash them away.
These colonies can consist of literally millions of individuals that are constantly working and producing heat. This heat is retained because of the insulation provided by the ground.
To cool the colony, the termites excavate a cellar portion that goes all the way to the damp soil just above ground water. They use the excavated soil to build their towers. In the main colony rooms, between the cellar and the vent tubes, the termites maintain the colony queen, nursery, food stores and the colony members.
Since warm air rises, the warm air from the colony room rises up through the vents. There is a chimney effect that helps pull this air out because of the height and diameter of the vents. But the flow of upward warm air sucks the damp cool air from the cellar up through the living chambers, cooling the colony.
What is of interest in Mozambique, Africa, is that when the termites mine out the cellar, they tend to carry only the smallest-size soil particles to the surface.
We call soil with the tiniest particles clay. Soil with larger particles we call sand.
Thus the mounds, or vents, are constructed from tiny clay particles, although the predominant surface soil in Mozambique is sand.
Mozambique is a desert country with few building materials. Wood is scarce. Brick is hard to obtain because there are no clay deposits, which are required to manufacture brick. Recently, student engineers discovered the termite mounds were about 70 percent clay.
The normal soil in Mozambique is less than 10 percent clay. A clay content of at least 15 percent is required to make bricks.
This team of student engineers from Brigham Young University, working with Care for Life, a nonprofit group in Mozambique, has designed a way to make a sturdy long-lasting brick from the soil from termite mounds. These bricks are mostly being used to build latrines that can withstand the monsoon rains and harsh summer heat, and to improve sanitation for remote villages.
So the next time someone asks you, “What good are termites?” you tell them they help build latrines for people in remote areas of Africa. They will probably look at you about the way you are looking at this article right now.