AUSTIN—Fire ants make for formidable arch villains. Working together in large colonies, they can kill a mouse and strip its skeleton clean in a matter of hours. They survive fires, quickly develop resistance to pesticides, and outswim floods by rafting together and floating away. They also use their bodies to build bridges across gaps in their paths. Now, a research team has examined what makes their bridges strong. Even without a leader, the ants are able to sense when their bridges are in trouble and react to strengthen these living structures, the scientists reported here today at the annual meeting of the Society for Integrative and Comparative Biology.Understanding how ants perform this maintenance could lead to better self-repairing materials, says David Hu, a mechanical engineer at the Georgia Institute of Technology in Atlanta and lead author on the new study.Natives of the flood plains of Brazil, fire ants cope with periodic downpours that require them to pack up and move. They and army ants have evolved the ability to clump together to form structures, such as rafts and bridges, to get to dry land again. “The formation of living structures such as the bridges is one of the most fascinating examples of the collective capabilities of ant colonies,” says Simon Garnier, a complex systems scientist with the New Jersey Institute of Technology, who was not involved with this study.Sign up for our daily newsletterGet more great content like this delivered right to you!Country *AfghanistanAland IslandsAlbaniaAlgeriaAndorraAngolaAnguillaAntarcticaAntigua and BarbudaArgentinaArmeniaArubaAustraliaAustriaAzerbaijanBahamasBahrainBangladeshBarbadosBelarusBelgiumBelizeBeninBermudaBhutanBolivia, Plurinational State ofBonaire, Sint Eustatius and SabaBosnia and HerzegovinaBotswanaBouvet IslandBrazilBritish Indian Ocean TerritoryBrunei DarussalamBulgariaBurkina FasoBurundiCambodiaCameroonCanadaCape VerdeCayman IslandsCentral African RepublicChadChileChinaChristmas IslandCocos (Keeling) IslandsColombiaComorosCongoCongo, The Democratic Republic of theCook IslandsCosta RicaCote D’IvoireCroatiaCubaCuraçaoCyprusCzech RepublicDenmarkDjiboutiDominicaDominican RepublicEcuadorEgyptEl SalvadorEquatorial GuineaEritreaEstoniaEthiopiaFalkland Islands (Malvinas)Faroe IslandsFijiFinlandFranceFrench GuianaFrench PolynesiaFrench Southern TerritoriesGabonGambiaGeorgiaGermanyGhanaGibraltarGreeceGreenlandGrenadaGuadeloupeGuatemalaGuernseyGuineaGuinea-BissauGuyanaHaitiHeard Island and Mcdonald IslandsHoly See (Vatican City State)HondurasHong KongHungaryIcelandIndiaIndonesiaIran, Islamic Republic ofIraqIrelandIsle of ManIsraelItalyJamaicaJapanJerseyJordanKazakhstanKenyaKiribatiKorea, Democratic People’s Republic ofKorea, Republic ofKuwaitKyrgyzstanLao People’s Democratic RepublicLatviaLebanonLesothoLiberiaLibyan Arab JamahiriyaLiechtensteinLithuaniaLuxembourgMacaoMacedonia, The Former Yugoslav Republic ofMadagascarMalawiMalaysiaMaldivesMaliMaltaMartiniqueMauritaniaMauritiusMayotteMexicoMoldova, Republic ofMonacoMongoliaMontenegroMontserratMoroccoMozambiqueMyanmarNamibiaNauruNepalNetherlandsNew CaledoniaNew ZealandNicaraguaNigerNigeriaNiueNorfolk IslandNorwayOmanPakistanPalestinianPanamaPapua New GuineaParaguayPeruPhilippinesPitcairnPolandPortugalQatarReunionRomaniaRussian FederationRWANDASaint Barthélemy Saint Helena, Ascension and Tristan da CunhaSaint Kitts and NevisSaint LuciaSaint Martin (French part)Saint Pierre and MiquelonSaint Vincent and the GrenadinesSamoaSan MarinoSao Tome and PrincipeSaudi ArabiaSenegalSerbiaSeychellesSierra LeoneSingaporeSint Maarten (Dutch part)SlovakiaSloveniaSolomon IslandsSomaliaSouth AfricaSouth Georgia and the South Sandwich IslandsSouth SudanSpainSri LankaSudanSurinameSvalbard and Jan MayenSwazilandSwedenSwitzerlandSyrian Arab RepublicTaiwanTajikistanTanzania, United Republic ofThailandTimor-LesteTogoTokelauTongaTrinidad and TobagoTunisiaTurkeyTurkmenistanTurks and Caicos IslandsTuvaluUgandaUkraineUnited Arab EmiratesUnited KingdomUnited StatesUruguayUzbekistanVanuatuVenezuela, Bolivarian Republic ofVietnamVirgin Islands, BritishWallis and FutunaWestern SaharaYemenZambiaZimbabweI also wish to receive emails from AAAS/Science and Science advertisers, including information on products, services and special offers which may include but are not limited to news, careers information & upcoming events.Required fields are included by an asterisk(*)Often the bridges lack sturdy supports and hang between leaves or reeds that vibrate in wind or water currents, so researchers long wondered how these seemingly flimsy structures stay up. Hu and his graduate student Sulisay Phonekeo collected wild fire ants and tested how their bridges survive vibrations.The ants naturally clump together and can be pulled like taffy into a bridge. Phonekeo suspended these living spans between the ends of two funnels and used time-lapse video to observe how they survived shaking at different frequencies. When he subjected the bridge to less than 20 vibrations per second, nothing happened. But more intense shaking caused the ants to spring into action. To form the bridge, the ants link legs. With each shake, the ants pull themselves closer together, tightening their grips on one another and shortening the bridge, Phonekeo reported at the meeting. “The ants are changing the material properties of the bridge by pulling their arms in,” Hu explains. By becoming stiffer, the bridge can “support more weight.”Ants strengthen shaky bridges in another way. Individuals scurrying along the bridge tend to change course and gather at the beginning and end of the bridge, helping dampen the effects of the vibrations. When holes or weak points do appear, ants mend the gap by linking together at that spot. In a sense, the ants become a very dynamic building material. “The ants don’t have an observer to point to a hole, they have to feel around and detect it,” Hu says. Next, he and Phonekeo will try to learn how the ants pinpoint weak spots.”This study is an important step toward understanding better how ants [form] their living architectures in response to environmental challenges,” Garnier says. Because the bridge is built and repaired in a completely self-organized manner, “the construction rules followed by the ants represent a formidable source of inspiration for people working on self-assembling robots and self-repairing materials.”*Clarification, 10 January, 10:49 a.m.: Although Simon Garnier’s lab is on Rutgers University’s Newark campus, he is part of the New Jersey Institute of Technology faculty, not the Rutgers one. read more

Go back to the e-newsletter >Four Pillars Gin has collaborated with the Rockpool Mixologists to craft a limited-edition gin for Qantas, aptly named the ‘Modern Australian Gin’.Rockpool Mixologists, Ryan Gavin, Max Gurtler and Jacob Dykes, along with Four Pillars’ distiller Cameron Mackenzie, handpicked the botanicals which include red and green Szechuan, quandong, macadamia nuts, fresh grapefruit peel, tangelos and Rosie Glow apples. Combined with the traditional Four Pillars botanicals, the result is an Asian-inspired, Modern Australian gin with softness and spice.The ‘Modern Australian Gin’ will be poured in the Qantas First lounges in Sydney, Melbourne and Los Angeles, as well as the Hong Kong and Singapore lounges. The Rockpool Mixologists have designed three special cocktails – Hanky Panky, Gin Spritzer and The Doctor’s Order – which will be featured in the Sydney and Melbourne First Lounge.The gin will also be poured throughout Rockpool Group restaurants across Australia and will be available to purchase through Qantas epiQure, via the Four Pillars website and at the Four Pillars Distillery.Cameron Mackenzie, Four Pillars Distiller said it was a great partnership that has resulted in an even greater product.“As it says on the side of the bottle, when the opportunity arose to make a gin with the Rockpool Mixologists for Qantas, how could we say no? We’re really excited to extend our Bartender Series and welcome the newest member of the family; the Modern Australian Gin,” said Mackenzie.“The gin itself is exceptional. The Asian spices give it a lovely warm mouthfeel, while the macadamia nuts give it softness and the apple and quandong give it freshness and a touch of the exotic. It’s delicious, it’s different and it will make a great drink, however you choose to enjoy it,” Mackenzie continued.The limited-edition drop is available to purchase for Qantas epiQure members for $80 at Qantas epiQure, or at the Four Pillars Distillery in Healesville or via the Four Pillars website, for $85 from 3 December 2015.Go back to the e-newsletter > read more