Termites are tiny insects that eat wood, and they need partners to digest it. Most termites cannot digest wood alone, and tiny one-celled living things called protists in a termite's gut help turn wood into food for the colony. Termites get help from fungi too. Decay fungi in rotting wood break down cellulose into smaller pieces before the termites bite, so termites eat decayed wood faster than sound wood. In forests, termites break down fallen trees and stumps and let their nutrients go back into the soil. They eat the soft part of the wood grain first and leave the harder part.
Young termites get their gut microbes from nest mates. Termites pass gut contents between nest mates, which is called trophallaxis. This shares food and also passes the cellulose-digesting protozoans along, so young termites get the microbes they need. Scientists call termites eusocial, and they use three traits for that word. Adults care for the young together, some individuals are sterile and work for the colony, and two or more generations overlap in the colony. A colony has three main castes: workers, soldiers, and the kings and queens that reproduce. Soldiers guard the colony, and queens lay the eggs. Worker termites find and eat the wood.
Leafcutter ants do not eat the leaves they cut. They use them to grow a fungus, and they eat the fungus. Leaves have little nitrogen, which the ants' fungus needs. Leafcutter gardens host bacteria that pull nitrogen out of the air, and the leaves get richer in nitrogen as they pass through the garden. A leafcutter ant colony can hold millions of ants, and the largest colonies have over 8 million. Only some ants farm, and all the fungus-farming ants live in the New World. They chew the leaf pieces into tiny bits before they add them to the garden.
Fungus-farming ants also fight garden pests. If they find a bad mold or bacteria they try to pluck it out. If they cannot, they apply antibiotics to it. The antibiotics come from glands on the ants or from bacteria growing on them. A Smithsonian scientist says an ant visits every square centimeter of the garden every few seconds. When a young queen starts a new nest, she carries a piece of the fungus garden in her mouth to start the new garden. In South America, a big leafcutter colony eats about as much fresh plant material each day as a cow.
A study in South Dakota measured what insects add to dung. Dung pats that the whole community of insects could use broke down about 30 percent more than pats kept from them. Tunnelling dung beetles drag dung underground and lay their eggs in brood balls made from it. As of April 2026, North America north of Mexico has about 170 species of dung beetle, and Vermont and New York surveys found 24 species on dairy, beef and grazing farms. Some countries, such as Australia and New Zealand, release dung beetles on purpose to help clear livestock dung from pastures. Without such helpers, a pile of cow dung can sit in a field for a very long time and smother the grass under it.
Black soldier flies came from warm regions and cannot survive cold well. In Utah they usually cannot overwinter outdoors, so year-round farms keep them in enclosed, netted buildings. Their larvae can finish waste much faster than ordinary composting, and they can eat dairy, meat and citrus that backyard compost piles usually leave out. The larvae give off heat as they eat and can reduce germs in the waste. As of January 2025, about 40 percent of food made for people in the United States never gets eaten, and the larvae are one way to turn some of that waste into soil booster and animal feed.
Earthworms live in soil and eat dead leaves and bits of soil, and they come in three kinds by where they live: surface worms in leaf litter, topsoil worms that tunnel sideways, and deep-tunnelling nightcrawlers that pull leaves down into the soil. The common nightcrawler came from Europe and is not native to the United States. Earthworms are helpful in crop fields, but some non-native worms harm forests. U.S. Department of Agriculture scientists found more earthworms in fields that were tilled less, where worms ate crop leftovers and mixed them with soil, so worm casts were used as a way to check soil health. Earthworm droppings are called casts, and they hold soil, bits of plants and tiny microbes.
Words to know
- cellulose: tough plant fiber
- trophallaxis: sharing gut food
- eusocial: tightly social
- antibiotics: germ-killing chemicals
- nightcrawlers: deep-tunnelling worms
