The Lives of Ants This page intentionally left blank Thea Lives of ANTS by Laurent Keller and Elisabeth Gordon translated by James Grieve 3 Great Clarendon Street, Oxford ox2 6dp Oxford University Press is a department of the University of Oxford. It furthers the University’s objective of excellence in research, scholarship, and education by publishing worldwide in Oxford New York Auckland Cape Town Dar es Salaam Hong Kong Karachi Kuala Lumpur Madrid Melbourne Mexico City Nairobi New Delhi Shanghai Taipei Toronto With offices in Argentina Austria Brazil Chile Czech Republic France Greece Guatemala Hungary Italy Japan Poland Portugal Singapore South Korea Switzerland Thailand Turkey Ukraine Vietnam Oxford is a registered trade mark of Oxford University Press in the UK and in certain other countries Published in the United States by Oxford University Press Inc., New York Q Laurent Keller and E´lisabeth Gordon 2009 English translation Q James Grieve 2009 The moral rights of the author have been asserted Database right Oxford University Press (maker) First published 2009 All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, without the prior permission in writing of Oxford University Press, or as expressly permitted by law, or under terms agreed with the appropriate reprographics rights organization. Enquiries concerning reproduction outside the scope of the above should be sent to the Rights Department, Oxford University Press, at the address above You must not circulate this book in any other binding or cover and you must impose the same condition on any acquirer British Library Cataloguing in Publication Data Data available Library of Congress Cataloging in Publication Data Library of Congress Control Number: 2008943416 Typeset by SPI Publisher Services, Pondicherry, India Printed in Great Britain on acid-free paper by CPI Anthony Rowe, Chippenham, Whiltshire ISBN 978–0–19–954186–7 13579108642 Acknowledgments The authors are extremely grateful to the Foundation Ernest Dubois for its generous support. Laurent Keller also acknow- ledges the Swiss National Foundation for its continuing support of his research. We thank Daniel Cherix, Christian Peeters, Francesco Mondada, and Ge´rard Jorland for their useful com- ments on the French version of the text. We would also like to express our gratitude to Latha Menon of Oxford University Press for her strong support and expert guidance, and to James Grieve for the difficult translation of the book. Ulrich Mueller made very valuable comments on the leaf-cutting ant section; and we are particularly grateful to Andrew Bourke for his close reading of the whole translation and his perceptive comments on it. Thanks, too, to Pierre and Chloe´ for having gone for so many months without their favourite veal blanquette and cheese souf- fle´, and to Marius and Le´onore for having uncomplainingly done without all that skiing. This page intentionally left blank Contents List of illustrations x Figure acknowledgements xii Introduction 1 Part I An Ecological Success Story 7 Chapter 1 Anywhere and everywhere 9 Chapter 2 On tastes and colours 13 Chapter 3 The secrets of success 17 Chapter 4 A huge impact on the environment 24 Chapter 5 A long long story 28 Part II Social Life 35 Chapter 6 The birth of the colony 37 Chapter 7 Division of labour 43 Chapter 8 Let slip the ants of war 51 Chapter 9 Flexible work arrangements 56 Chapter 10 Communication systems 60 Chapter 11 Family models 70 Chapter 12 Parasites and slave-makers 77 vii CONTENTS Part III Nowt So Rum as Ants! 83 Chapter 13 Army ants 85 Chapter 14 We work at the weaver’s trade 93 Chapter 15 Navigators who never lose their way 99 Chapter 16 Honeypots 106 Part IV Advantageous Liaisons 109 Chapter 17 Colonies and their livestock 111 Chapter 18 Ant trees 121 Chapter 19 Attines and fungus getting on famously 129 Part V Bloody Pests! 135 Chapter 20 Stand by for invaders! 137 Chapter 21 Supercolonies 148 Part VI Kith and Kin 157 Chapter 22 Genetic altruism and sociality 159 Chapter 23 Family feuds 164 Chapter 24 Nepotism or not? 172 Chapter 25 Caste struggles 175 Chapter 26 Anything goes 182 Part VII Sociogenetics 193 Chapter 27 Genes and family structure 195 Chapter 28 The genomics of behaviour 202 Chapter 29 So what’s so special about the genome of fire ants? 208 viii CONTENTS Part VIII High-tech Ants 215 Chapter 30 Computer-modelling behaviour 217 Chapter 31 Of ants and IT men 221 Chapter 32 Swarm robotics 226 Conclusion 233 Further reading 235 Species Index 241 General Index 244 ix List of illustrations Fig. 1 The shortest path 63 Fig. 2 Haplo-diploid heredity 166 Fig. 3 Parthenogenesis 187 Fig. 4 Cloning 190 Drawing 1 Great diversity 8 Drawing 2 Parasites 36 Drawing 3 Weaver ants (Oecophylla) 84 Drawing 4 Raising aphids 110 Drawing 5 Invasive ants 136 Drawing 6 Abnormal reproduction 158 Drawing 7 One genome, two phenotypes 194 Drawing 8 Ant robots 216 x This page intentionally left blank Figure acknowledgements Photographs in the plate section were taken by: 1. a. Alex Wild; b. Alex Wild 2. Alex Wild 3. a. Alex Wild; b. Alex Wild; c. Alex Wild; d. Alex Wild 4. a. Laurent Keller; b. Alex Wild; c. Laurent Keller; d. Alex Wild 5. a. Alex Wild; b. Alex Wild; c. Alex Wild; d. Alex Wild 6. a. Laurent Keller; b. Alex Wild; c. Daniel Kronauer; d. Daniel Kronauer 7. a. Daniel Kronauer; b. Alex Wild; c. Daniel Kronauer; d. Daniel Kronauer 8. a. Alex Wild; b. Alex Wild; c. Alex Wild 9. Alex Wild 10. Daniel Kronauer 11. a. Alex Wild; b. Alex Wild; c. Alex Wild; d. Alex Wild 12. Alex Wild 13. a. Alex Wild; b. Daniel Cherix 14. a. Christian Ko¨nig; b. Alex Wild; c. Elva Robinson; d. Christian Ko¨nig 15. a. Christian Ko¨nig; b. Christian Ko¨nig; c. Christian Ko¨nig 16. a. Francesco Mondada; b. Jean-Bernard Billeter & Michael Krieger; c. Francesco Mondada; d. Markus Waibel xii Introduction Since time immemorial, human beings have been fascin- ated, amazed, intrigued, and captivated by ants. And yet, at first glance, there is nothing particularly attractive about the tiny creatures. Unlike butterflies, they don’t have wings with vivid colour patterns; they cannot boast the iridescent wing-cases seen on many beetles. Nor do they produce things which human beings like to eat or wear, such as honey or silk. They don’t even chirp or sing like crickets or cicadas; and, unlike bees, they never go in for dancing. They do, however, have other characteristics which, in their way, are much more remarkable. For one thing, their social arrangements are quite extraordinary, almost unique among living creatures, and have often been compared to human soci- ety. William Morton Wheeler, the founder of American myrme- cology, wrote in Ants (1910): ‘The resemblances between men and ants are so very conspicuous that they were noted even by aboriginal thinkers.’ For another thing, ants are not only effi- cient, they are hard-working and thrifty, qualities which have always seemed like good reasons for seeing them as virtuous role models. 1 THE LIVES OF ANTS In c.1000 bc, King Solomon recommended them, in the Old Testament, as models of wisdom: ‘Go to the ant, thou sluggard; consider her ways, and be wise: Which having no guide, over- seer, or ruler, Provideth her meat in the summer, and gathereth her food in the harvest’ (Proverbs 6:6–8). The same way of seeing them turned up centuries later in La Fontaine’s fable ‘The Cicada and the Ant’. They are also mentioned in the Koran, which presents them as a highly developed race of beings, and in the Talmud, again as synonymous with honesty and virtue. The Greeks, too, Aristotle, Plato, and Plutarch, for instance, praised these social insects as wise and clever. The Roman naturalist Pliny the Elder devoted a whole chapter of his Historia naturalis to them, expatiating on their bravery and strength. He even mentions ants as big as dogs found in India or Ethiopia: they acted as guards outside gold-mines and killed any men who attempted to make off with the precious metal. These accounts are of course closer to fiction than to fact; but they do attest to the human appeal of ants, as well as to the fears they could engender. These figments of Antiquity’s imagination show that there was an awareness of how aggressive the insects could be. But what was uppermost in the ancient world’s appreciation of ants was how they could communicate with one another, devise their division of labour, and construct nests of such architectural complexity—which the natural historian Aelian compared to palatial residences. The effect of these tiny creatures on human imagination was such that they inspired many a myth and became incorporated into belief systems. The Dogon peoples of West Africa saw them as the wives of the god Amma and the mothers of the first humans. They were also central to traditional rituals, for ex- ample among the Wayana-Apalai peoples of Brazil, Surinam, and French Guyana, where a boy reaching puberty had to demonstrate that he was worthy of adult status by wearing a sling full of fire ants round his torso or tied to his back, thus 2 INTRODUCTION proving he had the courage and endurance to withstand the bites from these very aggressive creatures. Literature and film Nowadays ants have lost their previous importance in legend and ritual, but instead they figure prominently in books and films.