Ants, those 10,000 species of Hymenoptera that make up the Formicidae family, arose from the same branch as the Vespidae in tropical areas around the world. From these regions, they have spread to populate all continents and all environments. They have also shown an extraordinary degree of adaptability. For example, there are marked differences between the jaws of different genders, depending on the adaptability of the food resources to which a particular genus has adapted.
Ants can be between 1 millimeter and 4 centimeters (0.03 to 1.57 inches) long. Its social organization is among the most perfect in the world, truly remarkable, in fact, considering that some communities can reach a million individuals, each active, each assigned to his own special task and all living together in harmony. Most of a colony is made up of sterile female workers with stunted wings. The older ones leave the nest and sow in search of food for the entire colony, while the younger ones feed the larvae and the queens, many of which number more than one. Fertile males and females destined to become queens initially have wings. During the mating flight, the queen is fertilized. After this, the new socially useless males die while the fertilized queens shed their wings and lay their eggs in a nest that they build themselves, and in which they will raise their first offspring of workers, thus starting a new colony. As with bees, it is the workers who leave the nest and look for food. They store as much as possible in their stomachs, which then in effect serve as a common stomach. Everything they do not need for their own sustenance will be passed on to the members of the colony.
Ants have an excellent sense of direction and, with the characteristics of the landscape and the position of the sun to guide them, they can usually find their way back to a good food source when they want to settle in stores. However, a crucial function, such as the provision of food, is generally not left to the memory of an individual ant. Workers use the odorous secretions of special glands to “mark” their way back to the nest, and these secretions serve to guide others in the colony. Other scent signals serve to warm the colony from an approaching enemy, although in this situation many species prefer to sound an audible alarm by joining two petiole segments, which are shaped appropriately for that purpose.
Unlike most social insects, ants welcome insects from other families, even invertebrates belonging to other groups, such as spiders or millipedes, into their nests. Sometimes these are simply commensals: Acari, Coleoptera or Lepidotera in the larval or adult stage can settle in the ant nest for shelter and warmth, feeding only on the debris of the ants. However, living together does not always follow this restricted pattern. It can take any form, including parasitism. There are cases where the damage caused by the parasite to its nest is quite mild, when, for example, the parasite mimics the ant larva to be fed by the workers, and waits patiently for the workers to drop a drop. of food. during the process of trophalaxis. At the other end of the scale, there are situations where real damage is done to the ant colony. It is mercilessly exploited by parasites and, unable to provide enough food for ant larvae, visitors, and workers themselves, it eventually succumbs to the oppression of its unwanted hosts.
