Ants are a family (fam. Formicidae) of narrow-bodied wasps and bees within the order Hymenoptera. The head is prognathous, with strong multifunctional mandibles that are used for feeding, transporting food, defence, and manipulation of objects. The antennae are elbowed: there is a clear bend between the elongated first segment (scapus) and the other segments that form the funiculus. In most species, the antennae have 11 or 12 segments. The first segment of the abdomen is connected to the three segments of the thorax: in Hymenoptera this is called the propodeum. The entire body region is called the mesosoma and three pairs of walking limbs occur here. Worker ants are wingless. Males and young, unfertilised queens of most species are winged. Species in order Hymenoptera typically have two pairs of wings. After fertilisation, queens lose their wings. At the end of the mesosoma, above the metacoxa, is a metapleural gland (in some species it is secondarily reduced). It is externally visible as a protrusion with an opening. The mesosoma is followed by a narrow waist (petiole), consisting of one or two segments. The petiole is the second segment and the postpetiole, when present, the third segment. The remaining abdominal segments of the body are the gaster. In most groups (subfamilies), a sting with a venom gland is developed, but in some the sting is reduced.

All ants are eusocial insects. They live in communities called colonies, which in ants are perennial. They consist of workers (sterile females), one or more queens (fertile females) and offspring (eggs, larvae, pupae). One of the characteristics of eusocial life is the division of labour within the colony – queens are responsible for reproduction, and workers for all other tasks. There is also a division of labour amongst workers, and in some species, workers in the colony are also clearly physically separated (worker polymorphism). During part of the season, young, unfertilised queens and haploid males also develop in the colony, which after a certain time fly out of the anthills and mate. In most species, queens find a suitable location and begin to lay eggs, thus establishing a new colony. In some species, queens join an existing colony after fertilisation or, with the help of workers, break away from the mother colony. Many species from temperate zones are socially parasitic – a parasitic ant species parasitises another ant species in the initial phase of colony establishment or throughout its entire life cycle. In some parasitic species, only the sexual individuals (queens and males) are developed. Ants are found in practically all terrestrial habitats; in some places they represent a large part of the animal biomass. Anthills, ant dwellings, are located in a variety of habitats: in the soil (often under stones), in fallen wood on the ground, in various parts of living trees, in rock crevices, and within human dwellings. Most species are omnivorous. They can prey on other invertebrates or feed as scavengers. They often obtain food of plant origin through symbiosis with beaked insects (like aphids and other hemipteran insects), from which they obtain sweet plant liquid (honeydew), which they suck. In exchange for food, the ants protect these insects from predators. There are more than 14,000 known species of ants in the world, most of them in the tropics, and just over 150 species in Slovenia.