Gliding ants are

arboreal Arboreal locomotion is the locomotion of animals in trees. In habitats in which trees are present, animals have evolved to move in them. Some animals may scale trees only occasionally, but others are exclusively arboreal. The habitats pose nu ...

ant Ants are eusocial insects of the family Formicidae and, along with the related wasps and bees, belong to the order Hymenoptera. Ants evolved from vespoid wasp ancestors in the Cretaceous period. More than 13,800 of an estimated total of ...

s of several different

genera Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nomenclat ...

that are able to control the direction of their descent when falling from a tree. Living in the rainforest canopy like many other gliders, gliding ants use their gliding to return to the trunk of the tree they live on should they fall or be knocked off a branch. Gliding was first discovered for ''

Cephalotes atratus ''Cephalotes atratus'' is a species of arboreal ant in the genus ''Cephalotes'', a genus characterized by its odd shaped head. These ants are known as gliding ants because of their ability to "parachute" by steering their fall if they lose their ...

'' in the Peruvian rainforest. At least five genera in the subfamilies

Myrmicinae Myrmicinae is a subfamily of ants, with about 140 extant genera; their distribution is cosmopolitan. The pupae lack cocoons. Some species retain a functional sting. The petioles of Myrmicinae consist of two nodes. The nests are permanent and ...

Pseudomyrmecinae Pseudomyrmecinae is a small subfamily of ants containing only three genera of slender, large-eyed arboreal ants, predominantly tropical or subtropical in distribution. In the course of adapting to arboreal conditions (unlike the predominantly ...

, and

Formicinae The Formicinae are a subfamily within the Formicidae containing ants of moderate evolutionary development. Formicines retain some primitive features, such as the presence of cocoons around pupae, the presence of ocelli in workers, and lit ...

(mostly '' Camponotus'') display gliding of various degrees, in an example of

parallel evolution Parallel evolution is the similar development of a trait in distinct species that are not closely related, but share a similar original trait in response to similar evolutionary pressure.Zhang, J. and Kumar, S. 1997Detection of convergent and paral ...

. All species in the genus ''

Cephalotes ''Cephalotes'' is a genus of tree-dwelling ant species from the Americas, commonly known as turtle ants. All appear to be gliding ants, with the ability to "parachute" and steer their fall so as to land back on the tree trunk rather than fall t ...

'' (within Myrmicinae) tested to date show this ability, as do many species within Pseudomyrmecinae. Unique among gliding animals, ''Cephalotes'' (Myrminae) and Pseudomyrmecinae ants glide abdomen first. Formicinae ants glide in the more conventional head first manner, though. Gliding ants have been shown to have an 85%"Yanoviak S. P., and Dudley, R.
The role of visual cues in directed aerial descent of ''Cephalotes atratus'' workers (Hymenoptera: Formicidae).
''Journal of Experimental Biology.'' Vol. 209, 1177-1783. April 18, 2006. Accessed 2009-06-08. chance of landing successfully on the same tree, as opposed to 5% if they were simply parachuting like normal ants. This adaptation helps to keep ants from getting lost or killed on the forest floor, away from their treetop nests. During a fall, gliding ants use visual cues to locate tree trunks. Specifically, they orient to light-colored columnar objects that sharply contrast the darker background of foliage in the forest. Tropical trees often have light-coloured bark and frequently are covered with white lichens, thus they provide the most conspicuous targets. In a typical fall a descent by a gliding ant is "J-shaped".Dudley, R., Byrnes, G., Yanoviak S.P., Borrell, B., Brown, R.M., and McGuire, J.A.
Gliding and the Functional Origins of Flight: Biomechanical Novelty or Necessity?.
" ''Annual Review of Ecology, Evolution, and Systematics.'' Vol. 38, 179-201. December, 2007. Accessed 2009-06-08. The ant will first randomly descend in

free fall In Newtonian physics, free fall is any motion of a body where gravity is the only force acting upon it. In the context of general relativity, where gravitation is reduced to a space-time curvature, a body in free fall has no force acting on ...

, then visually lock on to the tree trunk it wishes to land on. The glide ant then, while exhibiting a sort of parachuting behaviour to slow its fall, uses its flattened head, hind legs and abdomen like wings or a parachute to make a rapid adjustment to point its

abdomen The abdomen (colloquially called the belly, tummy, midriff, tucky or stomach) is the part of the body between the thorax (chest) and pelvis, in humans and in other vertebrates. The abdomen is the front part of the abdominal segment of the to ...

(or

head A head is the part of an organism which usually includes the ears, brain, forehead, cheeks, chin, eyes, nose, and mouth, each of which aid in various sensory functions such as sight, hearing, smell, and taste. Some very simple animals ...

) towards the tree trunk. The ant then turns upside down and lands on the trunk, head facing the earth. The period of free fall is thought to be used by the ants to slow down to a minimum viable glide velocity, to allow them to successfully direct their descent towards the tree. This explains why smaller ants have been observed to reach their trees sooner than do larger ants. A smaller body mass makes it easier to slow to the minimum viable glide velocity, allowing smaller ants to gain control of their falls more quickly. Many ants use long, flattened legs and wide, flanged heads to act as parachutes to control the direction of their descent, although controlled descent has also been observed in species of Pseudomyrmecinae that have more cylindrical bodies. Gliding is not observed in all arboreal ants. Some characteristics that may be evolutionarily correlated with gliding are: *Arboreal nesting *Frequent foraging at branch tips *Heavily armoured individuals *Wide range of abdominal movement *Good vision * Diurnal activity *Evolutionary origins in flooded forests

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