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Scientific classification

The ants are one of the most successful groups of insects, and are of interest because they form advanced colonies. They belong to the order Hymenoptera, and are particularly close relatives of the vespid and scoliid wasps. The first known ants appeared sometime during the later Cretaceous period. They are physiologically distinguished mainly by having sharply elbowed antennae, and by having a bead-like pedicel formed from the first few abdominal segments, which in wasps are joined to the thorax. Also, most ants are wingless, although this varies between individuals in a colony rather than between species.

Table of contents
1 Colonies
2 Development
3 Communication and behaviour
4 Types
5 Symbiotic relationships with ants
6 Cultural aspects
7 See also
8 External links


Ant colonies are eusocial, and are very much like those found in other such Hymenopterans, though the various groups of these probably developed sociality independently through convergent evolution. Eggs are laid by one or sometimes more queens, and most of these grow up to become wingless, sterile females called workers. Periodically swarms of new queens and males called alates are produced, usually winged, which leave to mate. The males die shortly thereafter, while the surviving queens either found new colonies or occasionally return to their old one.

Ant-hill from the Alps


Ants develop by complete metamorphosis, passing through larval and pupal stages before they become adults. The larval stage is particularly helpless - for instance it lacks legs entirely - because it does not need to care for itself. The difference between queens and workers, and between different castes of workers when they exist, is determined by feeding in the larval stage. Food is given to the larvae by a process called trophallaxis, where an ant regurgitates food held in a crop for communal storage. This is also how adults distribute food amongst themselves. Larvae and pupae need to be kept at fairly constant temperatures to ensure proper development, and so are often moved around various brood chambers within the colony.

A new worker spends the first few days of its adult life caring for the queen and young. After that it graduates to digging and other nest work, and then again to foraging and defense of the nest. These changes are fairly abrupt and define what are called temporal castes. In a few ants there are also physical castes - workers come in a spectrum of sizes, called minor, media, and major workers, the latter beginning foraging sooner. Often the larger ants will have disproportionately larger heads, and so stronger mandibles. In a few species the media workers have disappeared, so there is a sharp divide and clear physical difference between the minors and majors, sometimes called soldiers.

Communication and behaviour

A photo of an ant head taken with a
Scanning Electron Microscope ()
Ant communication is primarily through chemicals called pheromones, which because most ants spend their time in direct contact with the ground are more developed than in other Hymenopterans. So for instance when a forager finds food, on his way home (found typically through remembered landmarks and the position of the sun) she will leave a trail along the ground, which in short time other ants will follow. When they return home they will reinforce the trail, bringing other ants, until the food is exhausted, after which the trail is not reinforced and so slowly dissipates. A crushed ant will emit an alarm pheromone that in high concentration sends other ants nearby into an attack frenzy, and in lower concentration attracts them, while a few ants use what are called propaganda pheromones to confuse their enemies. And so forth.

Like other insects, ants smell with their antennae. These are fairly mobile, having as mentioned above a distinct elbow joint after an elongated first segment, and since they come in pairs provide information about direction as well as intensity. Pheromones are also exchanged as compounds mixed in with the food interchanged in trophallaxis, giving the ants information about one another's health and nutrition. Ants can also detect what task group (e.g. foraging or nest maintenance) each other belongs to. Of special note, the queen produces a special pheromone without which the workers will begin raising new queens.

Ants attack and defend themselves by biting, and in many species, stinging, in both cases sometimes injecting chemicals into the target. Of special note is formic acid.


There is a great diversity among ants and their behaviors. See list of ant genera (alphabetical) for an alphabetical compendium of wordwide ant genera.

Of special note:

The most primitive ants are the army ants and driver ants, from South America and Africa respectively. These do not form permanent nests, but instead alternate between nomadic stages and stages where the workers form a temporary nest (bivouac) out of their own bodies. Most ants form stationary colonies, usually dug into the ground or some other hollow. Colonies reproduce either through nuptial flights as described above, or by fission, where a group of workers simply dig a new hole and raise new queens. Colony members are distinguished by smell, and other intruders are usually attacked, with notable exceptions. other

Leaf-cutting ants on the
journey back to the nest.

Symbiotic relationships with ants

Human beings have had a mixed relationship with ants through most of history. On the one hand, ants have often been used in fables and children's stories to represent industriousness and cooperative effort. They can also be important for clearing out insect pests and aerating the soil. On the other hand, they can become minor annoyances or major pests themselves when they invade homes, yards, gardens and fields. Some species, called killer ants, have a tendency to attack much larger animals during foraging or in defending their nests. Human attacks are rare, but the stings and bites can be quite painful and in large enough numbers can be disabling. These can be especially problematic when introduced into areas where they are not native.

Termites, sometimes called "white ants," are in fact not closely related to ants, though they have a somewhat similar social structure. They comprise the order Isoptera.

Cultural aspects

The ant is often a symbol of industriousness as well as aggressiveness and vindictiveness, and ants are sometimes used as a cure for laziness (such as in Morocco). In parts of Africa, ants are the messengers of the gods. Ant bites are often said to have curative properties. Some Native American religions, such as Hopi mythology, recognize ants as the first people. Others use ant bites in initiation ceremonies as a test of endurance.

See also

External links

One of the main differences between Ant and Make is that Ant is controlled using XML files, where Make has its own Makefile format. See The official website of Ant (software).