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DevelopmentMissing image Ants_evacuating_eggs.jpg Meat eater ants recovering eggs from a disturbed nest 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, trophallaxisin which an ant regurgitates food previously held in its 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. Missing image Ant_hill02.jpg Meat eater ants ant hill 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 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. Most of the common ant species breed in the same way. All ants in the colonies are females to begin with, but only the Queen and breeding females have the ability to mate. The male ants, called drones, along with the breeding females are born with wings, and do nothing throughout their life except eat. At least, until the time for mating comes. At this time, all the breeding ants in the colony are carried outside (save for the queen) where other colonies of similar species are doing the same. Then, all the winged breeding ants take flight. Mating occurs in flight and the males die shortly afterward. The females, those that survive, land and find a suitable place to begin a colony. There, they chew off their own wings and begin to lay eggs, which they care for. The first workers to hatch are weak and smaller than later workers, but they begin to serve the colony immediately. They enlarge the nest, forage for food and care for the other eggs. And that is how a new colony starts. Communication and behaviour Ant communication is primarily through chemicals called pheromones. Because most ants spend their time in direct contact with the ground, these chemical messages are more developed than in other Hymenopterans. So, for instance, when a forager finds food on her way home (found typically through remembered landmarks and the position of the sun), it will leave a trail along the ground, which in a 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. Like other insects, ants smell with their antennae which is long and thin. These are fairly mobile, having 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 here is formic acid. TypesThere is a great diversity among ants and their behaviors. See list of ant genera (alphabetical) for an alphabetical compendium of worldwide ant genera.  Of special note:
Symbiotic relationships with antsMissing image
Ant_cultivating_aphids.jpg Ant cultivating aphids
Humans and antsAnts are useful for clearing out insect pests and aerating the soil. On the other hand, they can become annoyances when they invade homes, yards, gardens and fields. Carpenter ants damage wood by hollowing it out for nesting. Nests may be destroyed by tracing the ants' trails back to the nest, then pouring boiling water into it to kill the queen. (Killing individual ants is less than effective due to the secretion of pheremones mentioned above). 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. Ants have often been used in fables and children's stories to represent industriousness and cooperative effort, as well as aggressiveness and vindictiveness. 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. 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. Missing image Ant_hill.jpg Ants on ant hill See also
External linksMissing image Ant_trail.jpg An ant trail
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