Ants are small black, brown, red or yellow insects. Adult ants can be as small as 1 mm (1/16 to 1/32 inch) like the little black ant and the kidnapper ant, and grow to 13 mm (1/2 inch) like the carpenter ant. Ants are social insects which constitute the family Formicidae (or formicidae in French) and, with wasps and bees, are classified in the order Hymenoptera, suborder Apocrita. These eusocial insects form colonies, called anthills, sometimes extremely complex, containing from a few dozen to several million individuals. Some species form supercolonies of several hundred million individuals. Termites, sometimes called white ants for their formal and behavioral resemblance, are of the order Dictyoptera (suborder Isoptera) but are not close relatives.

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In 2013, more than 12,000 species were recorded but there are probably thousands more yet to be discovered. The participatory census, as it was carried out in 2019-2020 in the canton of Vaud, in Switzerland, could be a way to acquire new knowledge. A cosmopolitan family (the ant has colonized all terrestrial regions with the exception of Greenland and Antarctica), it reaches a high density in tropical and neotropical environments. Although ants represent less than one percent of insect species, their estimated population of a billion billion individuals is such that the mass of myrmecofauna exceeds the weight of humanity and represents 10 to 15% of the animal biomass in many habitats, this mass combined with that of termites representing a third of the animal biomass in the Amazonian forest. Their evolutionary success is largely due to their social organization, their genetic plasticity associated with the presence of numerous mobile elements in the genome, and their dietary opportunism. Among the more than 12,000 known species (the total number of species is estimated at more than 20,000, or even 30,000 and even 40,000 according to the myrmecologist Laurent Keller, several hundred new species being described each year), ants vary in size from 0.75 to 52 mm The largest species is the fossil Titanomyrma giganteum, the queen reaching 6 centimeters long and 15 cm wingspan. The largest worker (30 mm long) is Dinoponera quadriceps.

The longevity record for an ant is held by a queen of the black garden ant, Lasius niger, who lived 28 years and 8 months in a laboratory. The males (characterized by their small head and large eyespots) have a very short life and, not knowing how to feed themselves, die as soon as they have reproduced. The worker ant lives between three weeks and a year. The queen can live much longer, several years (up to 15 years for the red ant queen. Eggs are laid by one or sometimes more queens (ant species with a single queen are called "monogynous" and those with multiple queens are called polygynous). Certain species can tolerate, when the colony is large, several queens so distant that they never meet (we then speak of oligogynous species). Most individuals grow to become flightless, sterile females called “workers.” Periodically, swarms of new queens and males, usually with wings, leave the colony to breed. It is the nuptial flight which takes place, thanks to climatic factors, synchronously with the flight of the males, for all the nests of the same species and the same region, for a few hours. After mating, the males then die quickly (but their ejaculate survives for several years in the princesses' spermatheca), while the surviving queens, fertilized, lose their wings (often they tear them off themselves), generally sinking in the ground and begin to lay eggs, to establish new colonies or, sometimes, return to their native anthill. The density of nests varies greatly depending on the species and the environment, being notably linked to the availability of food. Colony sizes vary from one extreme to the other. The smallest colony has four individuals with a queen in the nest.

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Behaviours

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Ants exhibit a behavior found in termites, bees and other social insects, consisting of gathering large numbers of individuals to create a functional and rapid colony.

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Communication

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Communication between ants occurs primarily through volatile chemicals called pheromones. 39 glands emitting them have been listed. Pheromones are sometimes excreted in a lipophilic substance that naturally covers the entire body of the ant. Like other insects, ants capture these odorous compounds with their antennae. These are quite mobile. an elbow joint after a first elongated segment (the scape), allowing them to identify both the direction and intensity of odors. The main use of pheromones lies in the definition and location of olfactory “trails” intended to guide ants towards food sources (see below). Pheromones are also mixed with food exchanged by trophallaxy, each providing information about the health and nutrition of its conspecifics. Ants can also detect which work group (e.g. foraging or nest maintenance) one or the other belongs to. Analogously, a crushed or attacked ant will produce an alert pheromone whose high concentration causes an aggressive frenzy in nearby conspecifics or whose lower concentration is enough to attract them. In some cases, pheromones can be used to deceive enemies, or even to influence the development of individuals.

Some ants make sounds, this is called stridulation. These sounds make it possible, for example, to attract other workers to carry prey that is too heavy for an isolated individual. Some ants make sounds, this is called stridulation. These sounds make it possible, for example, to attract other workers to carry prey that is too heavy for an isolated individual. Some species also use visual communication. In Tetraponera for example, when the larvae need food, they simply move their heads so that a worker intervenes to provide them with liquid food from mouth to mouth. In weaver ants, when a worker begins building a new nest, she begins by grabbing a leaf to bend it. She will immediately be joined by her entourage who will have seen the scene and who will help her in her task. This is how they can join the edges of two sheets to weave them together.

 

Orientation

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Some ants can travel distances of up to 200 meters from their nest, leaving scent trails that allow them to find their way even in the dark. In hot, arid regions, these same ants that face desiccation must find the shortest possible route back to the nest. Diurnal desert ants of the genus Cataglyphis navigate by keeping track of direction as well as distance traveled measured by an internal pedometer that takes into account the number of steps taken and by evaluating the movement of objects in their visual field (optical flow). Directions are measured using the position of the sun (their compound eye has specialized cells capable of detecting polarized light from the sun), the moon, the stars, or the Earth's magnetic field. In 2011, Antoine Wystrach defended a thesis which showed that ants do not use individual visual cues, but the entire panorama of their visual field. This allows them to have precise and exact orientation in natural environments..

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What do ants eat?

Ants generally feed on: • leaves • fruits • sweet foods • aphids • dead organisms These food sources are generally found on the ground. Ants also enter the wood by digging galleries to establish their nest.

 

Bites

The stings of most ants are usually harmless, causing only minimal reactions. However, they can cause allergic reactions in certain cases. The following minor reactions may result around the sting site: • stinging pain • swelling • blisters • swelling • itching • redness. Allergic reactions occur within an hour of the sting and can cause: • redness of the skin • hives all over the body • swelling of the eyes, tongue, • chest pain, lips and throat • nausea • headache • fainting Allergic reactions can be life-threatening and should be treated by a doctor. Minor reactions will disappear within a week or two.

 

Where do ants live?

The surrounding areas of homes provide a number of ideal shelters for ants, including wood and soil. Ants make their nest in wood or in the ground, and dig galleries to establish their colony.

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How to prevent an ant infestation?

The first step is to clean your house regularly. Cleaning up spills, washing dishes and vacuuming regularly – these are just some of the steps you can take to prevent infestations of these insects. Ants can establish their colonies in holes and small galleries , in damp places.• Store food in closed containers. • Clean your house regularly. • Get rid of old, untreated wood.

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