insects of the
family Formicidae and, along with the related
bees, belong to the
evolved from wasp-like ancestors in the
Cretaceous period, about 99 million years ago, and
diversified after the rise of
flowering plants. More than 12,500 of an estimated total of 22,000
species have been classified.
 They are easily identified by their elbowed
antennae and the distinctive node-like structure that forms their slender waists.
colonies that range in size from a few dozen predatory individuals living in small natural cavities to highly organised colonies that may occupy large territories and consist of millions of individuals. Larger colonies consist of various castes of sterile, wingless females, most of which are workers (ergates), as well as soldiers (dinergates) and other specialised groups.
 Nearly all ant colonies also have some fertile males called "drones" (aner) and one or more fertile females called "
 The colonies are described as
superorganisms because the ants appear to operate as a unified entity, collectively working together to support the colony.
(video) Ants gathering food
Ants have colonised almost every landmass on
Earth. The only places lacking
indigenous ants are
Antarctica and a few remote or inhospitable islands. Ants thrive in most ecosystems and may form 15–25% of the
 Their success in so many environments has been attributed to their social organisation and their ability to modify habitats, tap resources, and defend themselves. Their long
co-evolution with other species has led to
Ant societies have
division of labour, 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.
 Their ability to exploit resources may bring ants into conflict with humans, however, as they can damage crops and invade buildings. Some species, such as the
red imported fire ant (Solenopsis invicta), are regarded as
invasive species, establishing themselves in areas where they have been introduced accidentally.