Ants, are classified in the family Formicidae. These insects are native to nearly all terrestrial habitats and all parts of the globe except for Antarctica, Iceland, Greenland, some parts of Polynesia, and a few remote Indian Ocean and Atlantic Ocean islands(3), and are often extremely abundant locally(2). Though there are over 8,800 species known (and perhaps over 11,000 more that have not been described)(3), ants generally have a distinctive body structure: while they have, like many insects, a head, thorax (the midsection), and abdomen (the rear section), their “waist” connecting their thorax to the main part of their abdomen is unusually thin and pinched (1,3). Most ants are also characterized by the presence of a metapleural gland, an organ that produces a chemical called phenylacetic acid that is used for fighting bacteria and fungi(2,3); this gland may have helped ants colonize the moist environments where most ant species now live(2). Like only a few other groups of insects, ants have evolved a complex system of social interaction that qualifies them as “eusocial” insects(2,3). They live and work together in multi-generational colonies that are generally organized in “castes” of queens and males (who reproduce) and worker females (who cannot reproduce)(2,3), communicating via a chemical communication system that may be more complicated than that of any other kind of animal(2). In addition to these extraordinary social structures, ants have complex and extremely important relationships with many other species, giving them a central role in ecosystems across the globe(2). Some ants have partnerships with fungi(2). Some ants defend plants from herbivores, help plants reproduce by pollinating their flowers and spreading their seeds, and help plants grow by turning over the soil (which keeps it rich and healthy)(1,2,3). In fact, many plants depend on ants for their survival(3). On the other hand, some ants are the primary plant-eaters in their environments(1,2), and in many cases ants are major predators of small animals(2). Although some ant species can be pests themselves(1,2), some are beneficial to humans by feeding on harmful crop pests(2)—and by serving as subjects for a wide range of scientific studies(2,3).

Formicidae and Myrmicidae (Ants)
Ants are small to medium-sized insects that usually live in the ground, within cavities of trees, or rotting wood of buildings. They are various shades of black, brown, or red. Ants are highly social insects, consisting primarily of sterile workers without wings. Ants tend to be omnivorous scavengers, although some species cut leaves for their underground fungus farms, while others tend aphids for their honeydew. Ants sometimes visit flowering plants for nectar, particularly those with extra-floral nectaries, such as Trumpet Creeper, Wild Senna, and Partridge Pea. Species observed on such wildflowers include Acrobatic ants, Mound ants, and Carpenter ants.

The Formicidae are the ants, social insects. Ants evolved from wasp-like ancestors in the mid-Cretaceous period between 110 and 130 million years ago and diversified after the rise of flowering plants. More than 12,500 out of an estimated total of 22,000 species have been described. They are easily identified by their elbowed antennae and a distinctive node-like structure that forms a slender waist. Ants form colonies that range in size from a few dozen predatory individuals living in small natural cavities to highly organised colonies which may occupy large territories and consist of millions of individuals. These larger colonies consist mostly of sterile wingless females forming castes of workers, soldiers, or other specialised types. Nearly all ant colonies also have some fertile males called drones and one or more fertile females called queens. 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 terrestrial animal biomass. 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 mimetic, commensal, parasitic, and mutualistic relationships. 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. Ants come into conflict with humans, as they can damage crops and invade buildings. Some species, such as the red imported fire ant, are regarded as invasive species, aggressively establishing themselves in areas where they are accidentally introduced.

Bolton (2003) gives the following list of general synapomorphies for the Formicidae (but note that several of these are not unique to ants and have evolved independently in other vespoids, and that several have been secondarily lost in certain ant lineages):

• Eusocial, with perennial colonies
• Wingless worker caste
• Females with prognathous heads
• Infrabuccal sac between labium and hypopharynx
• Antennae elbowed (geniculate) between the funiculus and the elongated scape (scape short in the primitive subfamilies Armaniinae and Sphecomyrminae)
• Metapleural gland in females
• Abdominal segment II differentiated, forming a petiole (weakly differentiated in the primitive subfamily Armaniinae)
• Wings of alate queens shed after mating
• Mating performed in mass nuptial flights
• Forewings always lacking cross-veins 3rs-m and 2m-cu

Morphological terminology follows Bolton (1994), on which much of this key is based. The term mesosoma is used in preference to alitrunk, to refer to the body part formed from fusion of the thorax and the first abdominal segment (i.e., thorax + propodeum). The promesonotum is that part of the mesosoma composed of the pronotum and the mesonotum. Metasoma refers to the apparent abdomen, comprising the segments posterior to the propodeum, i.e., abdominal segment 2 and succeeding segments. In ants abdominal segment2 forms a node- or scale-like petiole, which is separated by a constriction from the rest of the metasoma. In some species abdominal segment 3 is also node-like and in this case it is said to form a postpetiole.

 

The key has been designed to apply only to those ant species occurring in California but it should also work for most of western North America, excluding Arizona and New Mexico where additional genera occur.

 

1 Postpetiole present: abdominal segment 3 separated from segment 4 by a strong constriction and distinctly smaller in size, so that anteriorly the metasoma has two nodelike segments, the petiole and postpetiole .................................................................... 2

 

- Postpetiole absent: abdominal segment 3 separated from segment 4 by a weak to moderate constriction or by none at all, and when viewed in profile not distinctly smaller in size (height) than segment 4; metasoma anteriorly with a single, isolated node-like or scale-like segment ....................................................................................................... 26

 

2 Eye reduced to a single ommatidium or absent; antennal insertions fully exposed in a full-face view of head ( Ecitoninae ) ........................................ Neivamyrmex Borgmeier

 

- Eye very rarely reduced, usually consisting of multiple ommatidia; antennal insertions not fully exposed, covered partially by frontal lobes or medial extensions of the antennal sclerites, when the head is observed in full-face view ........................................... 3

 

3 Eye very large, eye length about one-half of head length (excluding mandibles); pronotum freely articulating with mesonotum ( Pseudomyrmecinae ) ............................. ....................................................................................................... Pseudomyrmex Lund

 

- Eye less than one-half head length; pronotum fused with mesonotum ( Myrmicinae ) ... ....................................................................................................................................... 4

 

4 Antenna with 6 segments, including a 2-segmented club ............................................. 5

 

- Antenna with 10 segments, including a 2-segmented club ......... Solenopsis Westwood

 

- Antenna with 11 segments; club variable ..................................................................... 6

 

- Antenna with 12 segments; club variable.. ................................................................ 14

 

5 Mandible elongate and linear, with an apical fork of two spiniform teeth ...................... ...................................................................................................... Strumigenys F. Smith

 

- Mandible short and subtriangular, with a multi-denticulate masticatory margin ........... ............................................................................................................... Pyramica Roger

 

6 Postpetiole attached to the dorsal surface of the following abdominal segment; petiole dorsoventrally flattened, not node-like in profile ........................... Crematogaster Mayr

 

- Postpetiole attached to the anterior face of the following segment; petiole node-like in profile, not dorsoventrally flattened ............................................................................. 7

 

7 Head in lateral view with a diagonal carina running from above the eye down toward the mandibular insertion; promesonotum with conspicuous tubercles or spines ......... 8

 

- Head in lateral view lacking such a diagonal carina; promesonotum without conspicuous tubercles or spines .................................................................................................9

 

8 Frontal lobes expanded laterally and covering the sides of the head below the eyes, in full-face view; body lacking erect pilosity.................................... Cyphomyrmex Mayr

 

- Frontal lobes not expanded laterally to cover the sides of the head; body with erect pilosity.............................................................................................. Acromyrmex Mayr

 

9 Antenna with a distinct 2-segmented apical club............................... Wasmannia Forel

 

- Antenna lacking a distinct 2-segmented apical club, either 3-segmented or indistinct.. .....................................................................................................................................10

 

10 Eye absent or rudimentary; propodeum unarmed, basal face rounding into declivitous face ................................................................................................ Solenopsidininew genus

 

- Eye well developed, with multiple ommatidia; propodeum angulate or spinose.......11

 

11 Lateral portions of clypeus, in front of the antennal insertions, developed in the form of a raised ridge or shield-wall; frontal carinae extending almost to the posterior margin of the head......................................................................... Tetramorium Mayr (part)

 

- Lateral portions of clypeus not developed as a raised ridge or shield-wall; frontal carinae very short or absent...............................................................................................12

 

12 Eye with short erect setae projecting between the ommatidia........ Formicoxenus Mayr

 

- Eye lacking erect setae................................................................................................13

 

13 Median portion of clypeus with a smooth, longitudinally excavate surface, and lacking carinae .............................................................................................. Leptothorax Mayr

 

- Median portion of clypeus with several longitudinal carinae......................................... ................................................................................................. Temnothorax Mayr (part)

 

14 Hind tibial spur finely pectinate (as seen at 50-100x magnification).........................15

 

- Hind tibial spur simple or absent.................................................................................17

 

15 Metanotal groove absent or very weakly impressed, not breaking the dorsal profile of the mesosoma; psammophore usually present............................ Pogonomyrmex Mayr

 

- Metanotal groove present and interrupting the dorsal profile of the mesosoma; psammophore absent...........................................................................................................16

 

16 Propodeum unarmed; mandible with more than 12 teeth ....................... Manica Jurine

 

- Propodeum armed with a pair of spines; mandible with 6-10 teeth .. Myrmica Latreille

 

17 Lateral portions of clypeus, in front of the antennal insertions, developed in the form of a raised ridge or shield-wall; apex of sting with triangular lamellate appendage...... ................................................................................................. Tetramorium Mayr (part)

 

- Lateral portions of clypeus not developed as a raised ridge or shield-wall; apex of sting without triangular lamellate appendage .....................................................................18

 

18 Petiole short and sessile, lacking well differentiated anterior peduncle and dorsal node; ventrolateral margin of head with sharp, longitudinal carina extending from mandibular base to posterolateral corner of head........................................... Myrmecina Curtis

 

- Petiole with anterior peduncle and dorsal node; ventrolateral margin of head without sharp, longitudinal carina ...........................................................................................19

 

19 Dorsum of head and mesosoma without standing pilosity .......... Cardiocondyla Emery

 

- Dorsum of head and mesosoma with standing pilosity ............................................... 20

 

20 Anteromedian portion of clypeus notably elevated and bounded by a pair of carinae that diverge anteriorly ................................................................................................ 21

 

- Anteromedian portion of clypeus not abruptly elevated and lacking a pair of anteriorly diverging carinae ........................................................................................................ 23

 

21 Propodeum unarmed ....................................................................... Monomorium Mayr

 

- Propodeum armed with a pair of teeth or spines ........................................................ 22

 

22 Antennal club 3-segmented; propodeal spiracle large and located close to the declivitous face of the propodeum, separated from latter by no more than the diameter of the spiracle .................................................................................................. Rogeria Emery

 

- Antennal club 4-segmented; propodeal spiracle relatively small and separated from the declivitous face of the propodeum by more than the spiracle diameter .......................... ....................................................................................................... Stenamma Westwood

 

23 Antennal club 3- (rarely 4-) segmented ....................................................................... 24

 

- Antenna lacking a distinct club ................................................................................... 25

 

24 In profile promesonotum domed and distinctly elevated above the propodeal dorsum; workers dimorphic ......................................................................... Pheidole Westwood

 

- In profile entire mesosoma dorsum flat to weakly convex, promesonotum not domed or markedly elevated above the level of the propodeum; workers monomorphic .......... ................................................................................................. Temnothorax Mayr (part)

 

25 Head narrow, longer than broad; mandible slender and triangular, outer margin not strongly curving towards the midline; psammophore absent ...... Aphaenogaster Mayr

 

- Head broad, subquadrate; mandible short and thick, outer margin strongly curving towards the midline; psammophore usually present ................................. Messor Forel

 

26 Pygidium (last visible abdominal tergite) flattened and bordered laterally with a row of peg-like teeth or spines that converge distally ( Cerapachyinae ).... Cerapachys F. Smith

 

- Pygidium (last visible abdominal tergite) convex and rounded, lacking a row of teeth or spines ..................................................................................................................... 27

 

27 Distinct constriction between abdominal segments 3 and 4; terga and sterna of abdominal segments 3 and 4 laterally fused ......................................................................... 28

 

- No constriction between abdominal segments 3 and 4; terga of abdominal segments 3 and 4 overlapping the corresponding sterna, not laterally fused with them ............... 30

 

28 Articulation of petiole (second abdominal segment) to third abdominal segment very broad; petiole without a distinct posterior face ( Amblyoponinae ) .................................. ..................................................................................................... Amblyopone Erichson

 

- Articulation of petiole (second abdominal segment) to third abdominal segment narrow; petiole with a distinct posterior face .................................................................. 29

 

29 Pronotum freely articulating with the mesonotum; abdominal tergite 4 not strongly enlarged and not curved ventrally; apex of metasoma directed posteriorly ( Ponerinae ) ....................................................................................................... Hypoponera Santschi

 

- Pronotum fused immovably to the mesonotum; abdominal tergite 4 strongly enlarged and curved ventrally; apex of metasoma directed anteriorly ( Proceratiinae ).................. .......................................................................................................... Proceratium Roger

 

30 Apex of metasoma with a circular orifice, often fringed with short setae (the acidopore) ( Formicinae )...................................................................................................31

 

- Apex of metasoma with a slit-shaped orifice ( Dolichoderinae )..................................38

 

31 Antenna with 9 segments ............................................................. Brachymyrmex Mayr

 

- Antenna with 11 segments ................................................................. Plagiolepis Mayr

 

- Antenna with 12 segments .........................................................................................32

 

32 Metapleural gland absent; antennal insertions well separated from the posterior clypeal margin; in profile mesosoma dorsum usually evenly convex........................ Camponotus Mayr

 

- Metapleural gland present; antennal insertions adjacent to the posterior clypeal margin; in profile promesonotum separated from the dorsal face of the propodeum by a distinct impression .....................................................................................................33

 

33 Maxillary palp segments 3 and 4 greatly elongated, segment 3 (counting from base) half the head length or more; psammophore present.............. Myrmecocystus Wesmael

 

- Maxillary palp segments 3 and 4 not greatly elongated, segment 3 much less than half the head length; psammophore absent .......................................................................34

 

34 Ocelli present; propodeal spiracle elliptical to oval....................................................35

 

- Ocelli absent or indistinct; propodeal spiracle circular to subcircular.......................36

 

35 Mandible triangular, with seven or more distinct teeth on the masticatory margin........ ............................................................................................................ Formica Linnaeus

 

- Mandible falcate (sickle-shaped) and lacking distinct teeth............ Polyergus Latreille

 

36 Dorsum of head and mesosoma with coarse setae, arranged in distinct pairs; eye situated in relatively anterior position, at or in front of midlength of side of head ............. ............................................................................................ Paratrechina Motschoulsky

 

- Pilosity on dorsum of head and mesosoma variable, but not arranged as coarse setae in pairs; eye situated in relatively posterior position, behind midlength of side of head ... .....................................................................................................................................37

 

37 Mandible with six teeth; antennal scape long, surpassing posterior margin of head by more than half its length; mesonotum in dorsal view strongly constricted behind pronotum .............................................................................................................. Prenolepis Mayr

 

- Mandible with seven or more teeth; antennal scape shorter, surpassing posterior margin of head by less than a third its length; mesonotum in dorsal view not strongly constricted behind pronotum...................................................................... Lasius Fabricius

 

38 Propodeum with a prominent conical tooth at the junction of the dorsal and declivitous faces; maxillary palp segment 3 elongate, subequal in length to segments 4-6; apical mandibular tooth much enlarged...................................................... Dorymyrmex Mayr

 

- Propodeum rounded or subangulate at the junction of the dorsal and declivitous faces, but without a conical tooth; maxillary palp segment 3 short, subequal in length to segments4; apical mandibular tooth not notably enlarged .............................................. 39

 

39 Mesosoma dorsum lacking standing pilosity .............................................................. 40

 

- Mesosoma dorsum with standing pilosity .................................................................. 41

 

40 Petiole flattened, plate-like, and without a conspicuous, dorsally protruding scale (petiole often overhung by the succeeding abdominal segment); dorsal face of propodeum much shorter than the declivitous (posterior) face ............................ Tapinoma Foerster

 

- Petiole with a well developed, dorsally protruding scale; dorsal face of propodeum subequal in length to declivitous face .............................................. Linepithema Mayr

 

41 In profile mesosoma dorsum without an impressed metanotal groove, the promesonotum and propodeum forming a continuous surface; workers variable in size within a colony ........................................................................................................... Liometopum Mayr

 

- In profile mesosoma dorsum interrupted by a well marked metanotal groove; workers showing little intra-colony size variation .................................................................... 42

 

42 Petiole lacking an erect scale; side of mesosoma with conspicuous microreticulate sculpture; dark brown-black, with contrastingly paler tarsi .......... Technomyrmex Mayr

 

- Petiole with well developed erect scale; side of mesosoma without conspicuous microreticulate sculpture; varying in color from yellowish-orange to dark brown, but without contrastingly paler tarsi ............................................................ Forelius Emery

A few genera are divided into parts, reflecting distinct characters sets outlined in Table 1.

 

1. Two distinct, long, narrow spines or lobes present on apical portion of abdominal sternum IX (Fig. 3a) or, if absent, then mandibles extremely elongated, distinctly longer than head, and volsella massive, claw-shaped, directed dorsally. Pygostyles absent........................................................... Cerapachyinae

 

- Spines or lobes absent on apical portion of abdominal sternum IX or the apical portion bilobed, with each lobe very wide (Fig. 3b). Mandibles not elongated, distinctly shorter than head. Volsella moderate, not claw-shaped, not directed dorsally. Pygostyles present or absent......................................................2

 

2. Abdominal segment III much smaller than segment IV in lateral view (Fig. 3c)....................................3

 

- Abdominal segment III nearly as large as segment IV in lateral view (Fig. 3d)......................................4

 

3. Hind tibia with two spurs (Fig. 3e)......................................................................... Pseudomyrmecinae

 

- Hind tibia with one spur or without spurs (Fig. 3f) ............................................................. Myrmicinae

 

4. Anal region of hind wing vestigial. Oblique mesopleural furrow reaching pronotum close to its posteroventral corner (Fig. 4a)...................................................................................................... Proceratiinae

 

- Anal region of hind wing well developed. Oblique mesopleural furrow not reaching pronotum, its anterior termination well separated from the pronotum (Fig. 1a)..................................................................5

 

5. Petiole (abdominal segment II) broadly and dorsally attached to abdominal segment III; dorsal constriction between petiole and abdominal segment III very shallow or indistinct in lateral view (Fig. 4b......... ........................................................................................................................................ Amblyoponinae

 

- Petiole (abdominal segment II) narrowly and ventrally attached to abdominal segment III; dorsal constriction between petiole and abdominal segment III deep in lateral view (Fig. 6a)...6

 

6. Scuto-scutellar suture usually longitudinally sculptured. Forewing clearly with cross vein 2rs-m (Fig. 1b); if vein weak then at least with vestigial branches on Radial sector and Media. Scape short, not reaching posterior margin of head in full-face view (Fig. 5c). Constriction between abdominal segments III and IV present in some cases.............................................................................................. Ponerinae

 

- Scuto-scutellar suture not longitudinally sculptured. Forewing usually without any trace of cross vein 2rs-m (Fig. 4c). Scape short (Fig. 4d) or long (Fig. 2a). Constriction between abdominal segments III and IV absent...........................................................................................................................................7

 

7. Many minute, serrate teeth present on masticatory margin of mandible (Fig. 4d), or, if teeth absent, then scape not reaching posterior margin of head in full-face view........................................ Dolichoderinae

 

- Several larger teeth present on masticatory margin of mandible (Fig. 2a). Scape long, distinctly exceeding posterior margin of head in full-face view (Fig. 2a)........................................................ Formicinae

Formicidae is prey of:
Amphisbaena caeca
Eleutherodactylus coqui
Eleutherodactylus richmondi
Eleutherodactylus portoricensis
Eleutherodactylus wightmanae
Eleutherodactylus eneidae
Melanerpes portoricensis
Todus mexicanus
Mimocichla plumbea
Margarops fuscatus
Anolis cuvieri
Anolis evermanni
Anolis stratulus
Anolis gundlachi
Leptodactylus albilabris
Myiarchus antillarum
Nesospingus speculiferus
Icterus dominicensis
Vireo altiloquus
Seiurus aurocapillus
Sphaerodactylus klauberi
Sphaerodactylus macrolepis
Diploglossus pleei
Anthracothorax viridis
Parula americana
Dendroica caerulescens
Dendroica discolor
Typhlops rostellatus
Eptesicus fuscus
Lasiurus borealis
Dendroica petechia
Loxigilla noctis
Trochilidae
Anolis gingivinus
Anolis pogus
Orthoptera
Araneae
Chilopoda

Based on studies in:
Puerto Rico, El Verde (Rainforest)

This list may not be complete but is based on published studies.

Formicidae preys on:
Eleutherodactylus coqui
Collembola
Auchenorrhyncha
Sternorrhyncha
fungi
fruit
seeds
dead leaves
detritus
Acari
fruit and seeds
nectar and floral
Zenaida asiatica
Vanessa cardui
Misumena vatia

Based on studies in:
Puerto Rico, El Verde (Rainforest)

This list may not be complete but is based on published studies.

Animal / guest
nymph of Alydus calcaratus is a guest in nest of Formicidae

Animal / predator
larva of Chrysotoxum is predator of brood of Formicidae
Remarks: Other: uncertain

Animal / predator
larva of Doros conopseus is predator of brood of Formicidae
Remarks: Other: uncertain

Animal / honeydew feeder
Formicidae feeds on honeydew Maculolachnus submacula

Animal / honeydew feeder
Formicidae feeds on honeydew Aphis sambuci

Animal / slave maker
Formicidae makes a slave of Aphidoidea

Animal / slave maker
Formicidae makes a slave of Pseudococcidae

Animal / slave maker
Formicidae makes a slave of Coccoidea

In Great Britain and/or Ireland:
Animal / associate
colony of anamorph of Hormiscium pithyophilum var. myrmecophilum is associated with nest of Formicidae

Animal / associate
larva of Microdon analis is associated with nest of Formicidae

Animal / associate
larva of Microdon mutabilis is associated with nest of Formicidae

Animal / predator
leaf of Pinguicula vulgaris is predator of adult of Formicidae
Other: minor host/prey

Animal / inquiline
larva of Smaragdina affinis is inquiline in nest of Formicidae
Remarks: Other: uncertain

Air scoops provide cooling: ants
 

Air scoops on the sides of ants cool them through evaporation.

     
  "Another reason ants succeed so well is that they're superb lawn-traversing machines. When this first one backs away from the shadow of the giant human and reenters the main part of the sunny, hot lawn, little air-scoops on its side automatically switch on. A mist of cooling water vapor puffs upward from them. That keeps the ant's temperature down, but it could also mean that the ant's nitrogen--the equivalent of our urine substances--would become overconcentrated." (Bodanis 1992: 39)
  Learn more about this functional adaptation.

Tongue sticks out elastically: ants
 

The tongue of ants protracts using elastic mechanisms.

   
  "The mouthparts are very important tools for almost any task performed by ants. In particular, the labiomaxillary complex is essential for food intake. In the present study we investigated the anatomical design of the labiomaxillary complex in various ant species, focusing on movement mechanisms. Six labial and six maxillary muscles with different functions control the several joints and ensure the proper performance of the labiomaxillary complex…the labial and maxillary muscles feature rather slow than fast muscle characteristics and do not seem to be specialized for specific tasks. Since glossa [tongue] protractor muscles are absent, the protraction of the glossa, the distal end of the labium, is a nonmuscular movement. By histological measurements of hemolymph volumes we could exclude a pressure-driven mechanism. Additional experiments showed that, upon relaxation of the glossa retractor muscles, the glossa protracts elastically. This elastic mechanism possibly sets an upper limit to licking frequency, thus influencing food intake rates and ultimately foraging behavior. In contrast to many other elastic mechanisms among arthropods, glossa protraction in ants is based on a mechanism where elasticity works as an actual antagonist to muscles. We compared the design of the labiomaxillary complex of ants with that of the honeybee and suggest an elastic mechanism for glossa protraction in honeybees as well." (Paul et al. 2002:39)

  Learn more about this functional adaptation.

Communication is resilient: Temnothorax ants
 

Communication behaviors in Temnothorax ants are resilient because they have evolved as anytime algorithms.

   
  "Tandem runs are a form of recruitment in ants. During a tandem run,  a single leader teaches one follower the route to important resources  such as sources of food or better nest sites. In the present  study, we investigate what tandem leaders and followers do,  in the context of nest emigration, if their partner goes missing.  Our experiments involved removing either leaders or followers  at set points during tandem runs. Former leaders first stand  still and wait for their missing follower but then most often  proceed alone to the new nest site. By contrast, former followers  often first engage in a Brownian search, for almost exactly  the time that their former leader should have waited for  them, and then former followers switch to a superdiffusive search.  In this way, former followers first search their immediate neighbourhood  for their lost leader before becoming ever more wide ranging  so that in the absence of their former leader they can often  find the new nest, re-encounter the old one or meet a new  leader. We also show that followers gain useful information even  from incomplete tandem runs. These observations point to the  important principle that sophisticated communication behaviours may  have evolved as anytime algorithms, i.e. procedures that are  beneficial even if they do not run to completion." (Franks et al. 2010:1697)

  Learn more about this functional adaptation.

Colonies distribute food after famine: Temnothorax ants
 

Colonies of Temnothorax ants distribute food effectively and safely after famine using multiple techniques, including food dilution, strategic food location within community, and living 'silos'.

       
  "Resource distribution is fundamental to social organization, but it  poses a dilemma. How to facilitate the spread of useful resources but  restrict harmful substances? This dilemma reaches a zenith in famine  relief. Survival depends on distributing food fast but that could  increase vulnerability to poisons. We tested how Temnothorax  albipennis ants solve this dilemma in the distribution of honey  solution after 48 h of starvation in four colonies with individually  marked workers. We constructed the complete network of liquid food  transmission (trophallaxis) between individuals. Within the first 30 min  of famine relief, 95% of the workers received food and the distribution  rate was an order of magnitude faster compared to the controls. We  tested the assumptions of a simple analytical model that best fitted our  data. Good mixing during famine relief was facilitated by the movement  of internal workers away from the brood pile and the movement of  foragers with food away from the nest entrance. This is intriguing  because T. albipennis workers have spatial fidelity zones and in  the controls internal and external workers were segregated. We  discovered that colony vulnerability to poisons during famine relief  might be mitigated by: (1) the dilution of food from the same source  through mixing, (2) the concentration of food in workers positioned  midway between the colony centre and its periphery and (3) the existence  of living 'silos'. The latter are expendable foragers, who stay inside  the nest and store food during famine relief, thus acting as potential  disposable testers for food toxicity." (Sendova-Franks et al. 2010:473)

  Learn more about this functional adaptation.

Collaborating for group decisions: honeybees
 

Honeybees collaborate when foraging, selecting a new hive through knowledge sharing.

     
  "Researchers at the Univ. of Illinois at Urbana-Champaign, led by principal researcher Feniosky Pena-Mora, are looking at ways to improve human collaboration during disaster relief efforts. They are attempting to draw inspiration from the collaboration patterns that honeybees use in their decision-making process when selecting a new hive or foraging, ants' behavior when they are under threat, and how infectious diseases spread among human populations. The team includes biological, computer, and social scientists, and civil engineers. The team believes that civil engineers should be a fourth group of first-responders at disaster relief efforts involving critical physical infrastructures. The researchers will develop ad hoc communication networks to spread critical information among first responders, similar to how a virus spreads. Models of collaboration based on study of ants and bees may be useful in understanding the basic principles and best practices when developing strategies to coordinate knowledge sharing in chaotic social settings." (Courtesy of the Biomimicry Guild)
  Learn more about this functional adaptation.

Relationship provides nutrients, protection: ant-plants and ants
 

Ant-plants and their ant lodgers gain nutrients and protection thanks to their mutualistic relationship.

         
  "One group of plants, the ant-plants, provide even more lavish accomodation for their ant-lodgers. They are epiphytes, and are very common growing on the branches of mangroves. In such a position, without roots in the ground, they are in particular need of mineral nutrients. Their guests provide it. The ant-plant's stem is swollen into a globe the size of a football and armoured on the outside by prickles. Ants swarm all over it, scurrying in and out of holes on the surface. Within, there are a number of large interconnected chambers. Some are the ants' living quarters. There the queen sits, steadily producing her eggs, and there too are the nurseries where the young larvae are kept and reared. These apartments have smooth light-coloured walls. But other chambers are different. These have darker walls which are covered with small warty outgrowths. Here the ants deposit the remains of their insect meals and their droppings. Both are rich in phosphates and nitrates, exactly the nutrients that the plant badly needs since, hanging on the branches of a mangrove tree in a brackish swamp, it is cut off from the soil. It absorbs them through the walls of these compartments and so is able to flourish in one of the most difficult and impoverished of habitats for a plant. But it can only do so because its insect lodgers pay rent by feeding it." (Attenborough 1995:209-211)
  Learn more about this functional adaptation.

Collection Sites: world map showing specimen collection locations for Formicidae

Barcode of Life Data Systems (BOLD) Stats
                                                             

Specimen Records:	48,357
Specimens with Sequences:	35,037
Specimens with Barcodes:	31,063
Public Records:	4,439
Species:	4,210
Species With Barcodes:	3,546

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Ants (Order: Hymenoptera; Family: Formicidae) are highly social insects and are often associated in one way or another with plants. Ants sometimes form mutualistic relationships with plants, which may benefit from ant predation on plant herbivores or seed dispersal by ants. However, there are relatively few examples of pollination by ants.

In some cases, ants actually appear to interfere with pollination, sometimes reducing plant reproductive output: they may consume nectar without providing the plant with any reproductive benefit; they are aggressive toward other insects, including pollinators; they can destroy floral tissue; and their secretions may reduce pollen viability. Some plants appear to have evolved means of minimizing ant visitation to their flowers. In one example of ant interference with pollination, the ant, Crematogaster scutellaris, is a major predator of the fig wasp, which forms an obligate pollination mutualism with the Mediterranean fig tree (Genus: Ficus L.)