Ants are eusocial insects belonging to the family Formicidae, and the order Hymenoptera along with bees and wasps.
We find ants appearing in a considerable diversity in the fossil record across the globe during the Early Cretaceous and early Late Cretaceous.
Ants developed from Vespoid wasp ancestors during the Crestaceous era and diversified after the emergence of flowering plants.
More than 12,500 of an estimated 22,000 species have been classified.
They are easily recognized by their curved antennae and the characteristic knot-like structure that makes up their slender waists.
Ants form colonies ranging in size from a few dozen predatory individuals living in small natural cavities to highly organized colonies that can occupy large areas and comprising of millions of individuals.
Larger colonies consist of different castes of sterile, females Without wings, many of whom are workers (ergates) as well as soldiers (dinergates) and other specialized groups.
Almost all ant colonies also have some fertile males called “drones” (aners) and one or more fertile females called “queens” (gynecologists).
The colonies are known as superorganisms because the ants appear to act as a unit and work together to support the colony
Division of labor exist
Ant societies have division of labor, communication between individuals, and an ability to solve complex problems. These parallels with human societies have long been an inspiration and subject of study.
Many human cultures make use of ants in cuisine, medication, and rituals. Some species are valued in their role as biological pest control agents.
Division of labor exist in the ant society, and communication among them as well as their ability to solve complex problems exist also. These parallels with human societies have long been an inspiration and subject of study. Many human cultures make use of ants in medication, cuisine and rituals. Most speciesare valuable in their role as biological pest control agents.
Nearly every landmass on Earth have been colonised by ant colony, it’s only Antarctica that hasn’t been colonised by ants. Ants may also from 15% to 25% of the terrestrial animal biomass, as a result of their ability to survive in various ecosystems.
Scientific Classification
- Scientific Name: Formicidae
- Kingdom: Animalia
- Phylum: Arthropoda
- Class: Insecta
- Order: Hymenoptera
- Infraorder: Aculeata
- Superfamily: Formicoidea
- Family: Formicidae, Latreille, 1809
Distribution
Ants are found on every continent with Antarctica as an exception and only a few large islands such as, Iceland, Greenland, parts of Polynesia, and the Hawaiian Islands lack native species of ants.
Ants occupy a variety of ecological niches and use many different food resources as direct or indirect herbivores, predators and scavengers.
Most ant species are omnivorous generalists, but some are specialized feeds. Their ecological dominance is evident in their biomass: ants contribute an estimated 15% to 20% (on average and almost 25% in the tropics) to terrestrial animal biomass, thus surpassing that of vertebrates.
Ants are between 0.03-2.0 inches in size, the largest species is the fossil Titanomyrma giganteum, the queen of which was 6 centimeters long and had a wingspan of 5.9 in.
The color of ants varies. Most ants are red or black, but some species are green, and some tropical species have a metallic sheen. There are currently more than 12,000 known species (with higher estimates of potential existence of around 22,000; see Article List of Ant Genera), with the greatest diversity in the tropics.
Taxonomic survey or analysis continue to solve the classification and systematics of ants. Online databases of ant species, including AntBase and the Hymenoptera Name Server, help keep track of known and newly described species.
The relative ease with which ants in ecosystems can be sampled and examined has made them useful as indicator species in biodiversity studies.
The table below shows the different number of species in different continent.
| Region | Number of species |
|---|---|
| Neotropics | 2, 162 |
| Nearctic | 580 |
| Europe | 180 |
| Africa | 2, 500 |
| Asia | 2, 080 |
| Melanesia | 275 |
| Australia | 985 |
| Polynesia | 42 |
Morphology (Structure)
Ants like other insects have exoskeleton which forms an external covering that provides a protection around the body and it serves as a point where muscles are attached, which contrast with the endoskeleton of humans and other vertebrates.
Generally, insects unlike humans, don’t have lungs that aids in respiration, rather these gases like carbon dioxide, oxygen and other gases pass through the exoskeleton through tiny valves known as Spiracles.
Insects also do not have closed blood vessels; Rather, they have a thin, long, perforated tube that runs along the top of the body (called a “dorsal aorta”) which works like a heart, pumping hemolymph towards the head, which stimulates the circulation of internal fluids.
The nervous system is made up of a ventral nerve cord which runs the length of the body, with multiple ganglia and branches extending to the extremities of the limbs along the way.
Head
Ants head houses many sensory organs. They also have compound eyes like most insects which are made up of several minute lenses which are connected together.
Ant eyes are good at detecting acute movements, but they do not provide a high-resolution image. They also have three simple eyes called Ocelli on the top of the head that sense light levels and polarization.
Ants have blurred vision, as compared to vertebrates, especially in smaller species and some subterranean taxa are completely blind. However, some ants, like the Australian bulldog ant, have excellent vision and are able to distinguish the distance and size of objects moving nearly a meter away.
Thorax
The legs and wings of ants are linked to the thorax which is known as mesosoma. The only set of ants that have wings are the reproductive females or queens.
Communication
The communication among ants is possible through the use of Pheromones, touch and sound. The perception of smell in ants takes place in mobile, thin, long antennae.
The antennae which are paired usually provide information regarding intensity and direction of scents. As most ants live on ground, they make use of the surface of the soil to leave trails of pheromone which may be followed by fellow ants.
Defence
Ants attack and defend themselves by biting and stinging, frequently injecting or spraying chemicals in many species such as formic acid in formic acid ants, alkaloids and piperidines in fire ants, and a variety of protein components in other ants.
Bullet ants (Paraponera) in Central and South America are considered to posses the most painful stings of all insects, although they are usually not fatal to humans. This sting receives the highest rating for the Schmidt sting pain index.
Locomotion
Most ants migrate on foot. Some species can jump, for example, Jerdon’s leaping ant (Harpegnathos saltator) can jump by synchronizing the action of its middle and rear pairs of legs.
There are several types of gliding ants, including Cephalotes atratus; This can be a common trait in tree ants with small colonies. Ants with this ability can control their horizontal movement to catch tree trunks as they fall from the forest canopy.
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