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 these workers find food, take care of the young, and build and defend the nest. Some colonies have workers of different sizes, called majors and minors, that do different jobs. The queen is the largest ant in the colony, and she is the ant that lays the eggs. Ants range in size from tiny to about an inch long.

In ants, an unfertilized egg becomes a male, and a fertilized egg becomes a female, which can be a queen or a worker. An ant grows from an egg to a larva to a pupa and then to an adult, and from egg to adult it takes about six to ten weeks. A larva has no legs and looks like a soft white worm. It cannot feed itself, and adult ants feed and clean it. 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.

Males appear for a short time each year and do nothing in the colony except mate. Young queens and males fly out to mate in a mating flight, and in most species a queen mates only once and never needs to mate again. After mating, a young queen loses her wings and looks for a place to start a new nest. A new queen raises her first workers, and then they take over the work of the nest. Some 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.

Ants do not see very well, and they find their way mostly by smell and touch, using two antennae to smell and to touch things. 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 a colony is attacked, ants make alarm chemicals that call other workers to help defend the nest, and ants also pass messages with smells, touch and vibrations.

When a flood comes, fire ants cling together and float in a group, and 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, so stay away from fire ant 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, tell a grown-up.

Some ants build, farm and make partners. Weaver ant workers use their own larvae like needles: the larvae make silk that stitches leaves together to form the nest. Leafcutter ants carry leaf pieces to their nest and use them to grow a fungus garden, and they eat only the fungus they grow. Many ants 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. Some plants give ants food and homes, and acacia trees with swollen thorns host ants that protect them from plant-eating animals and from competing plants. Ants also 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

• colony: big ant group
• larva: baby ant
• pheromones: scent chemicals
• budding: starting new nests
• honeydew: sweet liquid