Invertebrates
Termite
Infraorder Isoptera · also called white ant, wood ant
Termites have a public-relations problem. Most people know them only as the insects that eat houses, and picture them as a kind of pale ant. Both impressions are wrong. Termites are social cockroaches, only a handful of species touch buildings, and as a group they are among the most important animals on land.
Overview
Termites are an infraorder of about 3,000 species, found on every continent but Antarctica and most diverse in the tropics. They eat dead plant matter — wood, litter, grass, dung — that they cannot digest without help from gut microbes or, in some groups, a farmed fungus. They are not ants: they were reclassified into the cockroach order in the 2000s.
The colony
A colony runs on blind, sterile workers and soldiers with armoured heads or glue-squirting snouts, all serving a queen whose swollen body can lay tens of thousands of eggs a day for 20 years or more.
Fungus farms and skyscrapers
The Macrotermes group grows fungus on combs of chewed wood inside the mound. Some mounds reach 8 metres — the tallest structures any animal builds — and work as passive air conditioning, holding the fungus garden near 30 °C.
Why they matter
In tropical soils, termites can outweigh all the wild mammals combined, recycling dead plant matter, building fertile soil, and feeding aardvarks, pangolins, numbats, and chimpanzees.
Status
Least Concern — one of the most successful groups of animals on Earth. Only about 30 species are pests.
Termite: common questions
Are termites just white ants?
No, and the old name is misleading. Ants are in the order Hymenoptera, alongside bees and wasps, and evolved social living from a wasp-like ancestor. Termites are in the order Blattodea, the cockroaches, and DNA and anatomy show they are essentially a lineage of cockroaches that became fully social, so a termite is more closely related to the cockroach in your kitchen than to any ant. The confusion is understandable because both live in large colonies with workers and soldiers, but the resemblance is convergence, two groups arriving at the same solution. Quick tells — termites have straight bead-like antennae and a thick waist, ants have elbowed antennae and a pinched waist.
How do termites digest wood?
They cannot, at least not by themselves; no animal makes the full set of enzymes needed to break down the cellulose and lignin in wood. Termites solve this with partners. The lower termites carry a community of specialised protozoa and bacteria in an enlarged hindgut that ferment the wood particles into usable nutrients, a partnership so complete that a termite deprived of its gut microbes starves on a full stomach of wood. The higher termites, including the mound-building fungus growers, instead cultivate a fungus outside their bodies that does the digestion, and they eat the fungus and the partly rotted comb.
Why do termite mounds get so tall?
The mound is not where most of the termites live; the colony is in a nest below ground, and the mound above it is a climate-control chimney. Metabolic heat from millions of termites and, in fungus-growers, from the fungus garden, drives air up through the mound, drawing fresh air in through the base and porous walls, so the structure ventilates itself and buffers temperature swings between day and night and across seasons. Keeping the fungus garden and the brood within a narrow band around 30 degrees Celsius is essential, and a taller mound with more surface area and a bigger thermal mass does it better. The flattened, north-south-aligned mounds of the Australian magnetic termite are a variation on the same theme for a floodplain that cannot drain.
Are all termites pests?
Far from it. Of roughly 3,000 species, only around 30 do significant damage to buildings and crops, chief among them the Formosan subterranean termite and several drywood termites, and those cause billions of dollars of structural repair worldwide each year. The vast majority of termites live in forests, savannas, and grasslands where they are one of the most important recyclers on the planet, breaking down dead wood and plant litter, aerating and fertilising soil, and feeding aardvarks, aardwolves, numbats, pangolins, many birds, and, through tool-assisted fishing, chimpanzees. In much of Africa and Asia the winged reproductives are also collected and eaten by people.