Ants

The word "ant" is derived from ante, emete of Middle English which are derived from ǣmette of Old English, and is related to the dialectal Dutch emt and the Old High German āmeiza, hence the German Ameise. All of these words come from West Germanic *ēmaitijǭ, and the original meaning of the word was "the biter" (from Proto-Germanic *ai-, "off, away" + *mait-"cut"). The family name Formicidae is derived from the Latin formīca ("ant") from which the words in other Romance languages, such as the Portuguese formiga, Italian formica, Spanish hormiga, Romanian furnică, and French fourmi are derived.

It has been hypothesised that a Proto-Indo-European word *morwi- was used, cf. Sanskrit vamrah.   Latin formīca,Greek μύρμηξ mýrmēx, Old Church Slavonic mraviji, Old Irish moirb, Old Norse maurr, Dutch mier

The family Formicidae belongs to the order Hymenoptera, which also includes sawflies, bees, and wasps. Ants evolved from a lineage within the aculeate wasps, and a 2013 study suggests they are a sister group of the Apoidea. In 1966, E. O. Wilson and his colleagues identified the fossil remains of an ant (Sphecomyrma) that lived in the Cretaceous period. The specimen, trapped in amber dating back to around 92 million years ago, has features found in some wasps, but not found in modern ants. Sphecomyrma possibly was a ground forager, while Haidomyrmex and Haidomyrmodes, related genera in subfamily Sphecomyrminae, are reconstructed as active arboreal predators.After the rise of flowering plants about 100 million years ago they diversified and assumed ecological dominance around 60 million years ago. Some groups, such as the Leptanillinae and Martialinae, are suggested to have diversified from early primitive ants that were likely to have been predators underneath the surface of the soil.

During the Cretaceous period, a few species of primitive ants ranged widely on the Laurasian supercontinent (the Northern Hemisphere). They were scarce in comparison to the populations of other insects, representing only about 1% of the entire insect population. Ants became dominant after adaptive radiation at the beginning of the Paleogene period. By the Oligocene and Miocene, ants had come to represent 20–40% of all insects found in major fossil deposits. Of the species that lived in the Eocene epoch, around one in 10 genera survive to the present. Genera surviving today comprise 56% of the genera in Baltic amber fossils (early Oligocene), and 92% of the genera in Dominican amber fossils (apparently early Miocene).

Termites, although sometimes called 'white ants', are not ants. They belong to the sub-order Isoptera within order Blattodea. Termites are more closely related to cockroaches and mantids. Termites are eusocial, but differ greatly in the genetics of reproduction. The similarity of their social structure to that of ants is attributed to convergent evolution.Velvet ants look like large ants, but are wingless female wasps.

Ants may use the corners of their nest as 'toilets', a new study suggests. Tomer Czaczkes and colleagues from University of Regensburg, Germany conducted an experiment to determine whether distinct brown patches they observed forming in ants' nests were feces. In the study, 21 white plaster nests were inhabited by 150-300 black garden ants (Lasius niger) for two months. Researchers fed the ants food dyed with either red or blue food colouring and observed the nests for the colourful feces.They found that one or two corners of each nest started to fill with feces that was the same colour as the food they were fed. The researchers found no other waste in these areas, such as uneaten food items, or nestmate corpses, suggesting that ants may use these areas as 'toilets.' They also discovered that the ants didn't just put their toilets anywhere - almost all the ants placed their toilets in the corners, 'phys.Org' reported. "The patches were not randomly distributed around the nest, but rather localised primarily in the corners of the chambers," researchers said. "For ants, which like us live in very dense communities, sanitation is a big problem," said Czaczkes. "Ants normally keep a very clean nest, and usually throw out dangerous rubbish, like food remains and corpses," Czaczkes said. The researchers suggest that perhaps the piled-up waste might be useful to the ants. "Some insects use feces for defence, as building materials, as manure for their crops, and as markings. Perhaps these toilets are also gardens for crops, or even stores for valuable nutrients," said Czaczkes. The study was published in the journal PLOS ONE.