Ants live together in big groups called colonies, and some colonies are huge, with thousands to millions of ants. Ants range in size from tiny to about an inch long. The queen is the ant that lays the eggs. Almost all the other ants you see are female workers that cannot lay eggs. Worker ants find food, take care of the young, and build and defend the nest. As of November 2026, about 20 quadrillion ants live on Earth.

How can so many ants act together? Ants do not see very well. They find their way mostly by smell and touch. Ants use scent chemicals called pheromones 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. If an ant colony is attacked, ants make alarm chemicals that call other workers to help defend the nest.

Food is shared, too. Ants eat many different kinds of food, such as nectar, seeds, fungus and insects. Ants can carry liquid food in their bodies and share it with nestmates by spitting it up. In honeypot ant colonies, special workers called repletes swell up to store sweet liquid food for the colony. Many ants also collect honeydew, a sweet liquid made by aphids, to eat, and some ants protect aphids from enemies and even carry them from plant to plant, so they keep getting honeydew.

Leafcutter ants grow their own food. They 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. A Texas leafcutter ant colony can hold up to about 2 million ants, and a large Texas leafcutter ant nest can reach about 20 feet (6 meters) underground. When a leafcutter queen starts a new garden, she carries a bit of her home colony's fungus in her mouth.

Young queens and males fly out to mate in a mating flight. After mating, a young queen loses her wings and looks for a place to start a new nest. In most species a queen mates only once, and she never needs to mate again. A new queen raises her first workers, and then those workers take over the work of the nest. In ants, an unfertilized egg becomes a male, and a fertilized egg becomes a female. A female can be a queen or a worker.

Ants can team up against danger too. 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. Some ants can sting, and all ants can bite. A fire ant sting can cause burning, itching and swelling. If an ant stings or bites you, tell a grown-up. Trouble breathing or a tight chest after a sting means getting medical help right away. To stay safe from fire ants, stay away from their mounds and from floating rafts of ants.

Some plants give ants food and homes, and the ants protect the plants. Ants also dig tunnels that mix and air the soil, and they spread plant seeds and help return nutrients to the soil. An ant colony can act like one living thing, a superorganism, because its members communicate and cooperate.

Words to know

• superorganism: one living thing
• pheromones: scent chemicals
• repletes: food-storing workers
• honeydew: sweet aphid liquid
• aphids: honeydew makers