How do ants work together? Ants live together in big groups called colonies, and some colonies are huge, with thousands to millions of ants. Almost all the ants you see in a colony are female workers that cannot lay eggs, and they find food, take care of the young, and build and defend the nest, while the queen is the ant that lays the eggs in a colony. Ants range in size from tiny to about an inch long, and ants are very strong for their size. They have strong jaws called mandibles that they use to carry things and to cut. As of November 2026, there are about 2.5 million ants for every person on Earth.

In 1959, E. O. Wilson and mathematician William Bossert discovered how ants communicate with chemical signals called pheromones. Ants also do not see very well, and they find their way mostly by smell and touch. Ants use these scent chemicals to warn each other of danger or lead each other to food. When an ant finds food, it lays a scent trail on the way home, and the pheromone makes other ants likely to follow the same path. Deneubourg's team gave Argentine ants a bridge with two branches, one twice as long as the other, between nest and food, and within a few minutes the colony usually chose the shorter branch.

Where do ants live, and how do their nests differ from one kind of ant to another? Ants make their nests in several places: underground, in mounds, or in trees. A large Texas leafcutter ant nest can reach about 20 feet (6 meters) underground, and the nest has a ventilation system in which fresh air comes in through outer tunnels, while stale air and heat leave through central passages above the fungus gardens. Army ants have no permanent nest, and they keep moving to new places, and their bivouacs, which are their temporary nests, are made of living workers clinging together by specialized hooks on their feet, with colonies that alternate between two regular phases, a nomadic phase and a stationary phase.

When a flood comes, fire ants cling together and float in a group. A fire ant raft carries the whole colony, with the queen and young in the middle. It builds itself in less than 100 seconds, and it heals itself: if one ant is removed, others move in to fill the gap. Fire ant rafts can float on water for weeks at a time. Some ants can sting, and all ants can bite. A fire ant sting can cause burning, itching and swelling, and to stay safe from fire ants, stay away from their mounds and from floating rafts of ants. Trouble breathing or a tight chest after a sting means getting medical help right away, and if an ant stings or bites you, you should tell a grown-up.

How does a colony feed itself, and what do its members eat? Leafcutter ants carry leaf pieces to their nest and use them to grow a fungus garden, and in a leafcutter colony, small ants chew the leaf pieces into a paste for the garden, while leafcutter ants eat only the fungus they grow. A leafcutter queen carries a bit of her home colony's fungus in her mouth, and she uses it to start a new garden. A Texas leafcutter ant colony can hold up to about 2 million ants. Ants in general eat many different kinds of food, such as nectar, seeds, fungus and insects.

A baby ant, called a larva, has no legs and looks like a soft white worm. A queen ant lays thousands of eggs. In ants, an unfertilized egg becomes a male, and a fertilized egg becomes a female, a queen or a worker. How much food and what kind a larva gets helps decide how big it grows and whether it becomes a worker or a queen. A queen ant can live for several years, but many workers live only a few months, and in some species workers live only nine to ten weeks while in others they live more than six years. Some ant colonies start new nests by budding: a group of workers takes larvae from the old nest and raises them as new queens in a new place.

What do ants get from the other living things around them? Many ants collect honeydew, which is a sweet liquid made by aphids, and they eat it, and some ants protect aphids from enemies and even carry them from plant to plant, so that the ants keep getting honeydew. Some plants give ants food and homes, and the ants protect the plants. Acacia trees with swollen thorns host ants, and these ants protect the trees from plant-eating animals and from competing plants. Ants also help the soil by digging tunnels that mix and air it, and in addition they spread plant seeds and help return nutrients to the soil.

What do all of these jobs add up to? All ants live in advanced societies with cooperative parenting and division of labor, but their ancestors were solitary wasps. Worker ants groom and carry the young inside the nest, and worker ants defend their nests from other ants, while a new queen raises her first workers, and then they take over the work of the nest. Ants pass messages with smells, touch and vibrations, and an ant colony can act like one living thing, a superorganism, because its members communicate and cooperate. Cooperation in ant colonies is largely self-organized: coordination arises from interactions among individual ants.

Words to know

• superorganism: colony as one
• pheromones: scent signals
• bivouacs: temporary nests
• budding: starting new nests
• honeydew: aphids' sweet liquid
• larva: baby ant