Ant

Ants are eusocial insects of the family Formicidae and, along with the related wasps and bees, belong to the order Hymenoptera. They evolved from vespoid wasp ancestors in the Cretaceous period. More than 13,800 of an estimated total of 22,000 species have been described. Ants are easily recognised by their elbowed antennae and the distinctive node-like structure that forms their slender waists.

Ants form colonies that range in size from a few dozen individuals living in small natural cavities to highly organised colonies that may occupy large territories with nests containing millions of individuals. Some colonies can even reach hundreds of millions of individuals in super colonies. These colonies usually consist of sterile, wingless female workers, soldiers, and other specialised groups, along with fertile males called "drones" and one or more fertile females called "queens" (gynes). The colonies act like superorganisms, working together as a unified entity to support the group.

Ants have colonised almost every landmass on Earth, except for Antarctica and a few remote islands. They thrive in moist tropical ecosystems and can sometimes exceed the combined biomass of wild birds and mammals. Their success comes from their social organisation, ability to modify habitats, and strong defence strategies. Ant societies show division of labour, communicate with each other, and can even solve complex problems. These traits have inspired scientists and humans for a long time. Some cultures use ants in food, medicine, and rituals. While ants can help control pests naturally as biological pest control agents, some species, like the red imported fire ant (Solenopsis invicta), can become invasive species when they spread to new areas.

Etymology

The word ant comes from old languages like Middle English and Old English. Related words appear in German and other languages, all meaning something like "the biter."

The scientific name for ants, Formicidae, comes from the Latin word formīca, meaning "ant." This Latin root also influenced words for ants in languages such as Portuguese, Italian, Spanish, Romanian, and French. The study of ants is called myrmecology, a term that originates from the Ancient Greek word for ant.

Taxonomy and evolution

The family Formicidae belongs to the order Hymenoptera, which also includes sawflies, bees, and wasps. Ants evolved from a lineage within the stinging wasps. Scientists have found fossils of ants that lived millions of years ago, showing how they have changed over time. These ancient ants looked different from ants today, but they were the ancestors of all ants we see now.

Ants became very successful and spread all over the world. They live in colonies and work together, much like some other insects. Even though termites are sometimes called "white ants," they are not really ants and have different family trees.

Distribution and diversity

Ants are found everywhere on Earth except Antarctica. They live on all continents and most islands, missing only from places like Greenland, Iceland, parts of Polynesia, and the Hawaiian Islands. These tiny insects occupy many different environments and eat a variety of foods, acting as herbivores, predators, and scavengers.

Ants come in many sizes, from very small to quite large, and their colors range from yellow and red to brown and black. Over 13,800 ant species have been identified, and scientists believe there may be up to 22,000 different kinds. The greatest variety of ants is found in warm, tropical regions.

Morphology

Ants have unique body shapes that set them apart from other insects. They possess elbowed antennae and a narrow waist called a petiole, which connects their main body section (mesosoma) to their abdomen (gaster). Their bodies are divided into three main parts: the head, mesosoma, and metasoma.

Like all insects, ants have an external skeleton that protects their bodies and helps muscles attach. They breathe through small openings called spiracles and circulate fluids using a tube that acts like a heart. Their heads contain many sensors, including compound eyes for detecting movement and simple eyes (ocelli) for sensing light. They also have antennae that detect chemicals, air currents, and vibrations, along with strong jaws (mandibles) for carrying food and building nests.

Life cycle

The life of an ant begins from an egg. If the egg is fertilised, it will develop into a female; if not, it will develop into a male. Ants go through complete metamorphosis, which includes stages as a larva and a pupa, before becoming an adult. The larva is cared for by worker ants, who feed it and keep it safe.

After the larval stage, ants enter the pupal stage. Eventually, they emerge as adults. Ant colonies can live for many years, with queens living up to 30 years, while workers typically live from 1 to 3 years. In cooler regions, ants may go into hibernation during the winter to survive the cold temperatures.

Behaviour and ecology

Ants communicate with each other using pheromones, sounds, and touch. They leave pheromone trails on the ground to guide other ants to food. When a trail is blocked, ants explore new routes and mark the best path, helping the colony adapt.

Ants defend themselves by biting and, in many species, by stinging. Some ants, like bullet ants, have very painful stings. Others use special mandibles that snap shut quickly to catch intruders. Ants also protect their colonies from harmful substances and diseases by keeping them clean.

Relationship with humans

Ants help humans in many ways. They control pest populations and aerate the soil, moving about 1.5 tons of dirt per acre each year. In ancient China, weaver ants were used in farming to protect citrus crops.

Some ants, like army ants in Africa and South America, have been used in traditional medicine. Surgeons would place these ants on wounds, let them bite and hold the edges, then remove the bodies, leaving the heads to act as sutures. Ants can also be a food source in many cultures. For example, in Mexico, ant eggs called escamoles are a delicacy, and in Thailand, red ant eggs are used in salads. Some ants are also considered pests when they invade homes or damage crops.

Scientists study ants to understand biology and have even used their behaviors to inspire new technologies in computers and robotics. Ants have also appeared in stories, movies, and games, often symbolizing hard work and teamwork.