Research Interests - Social Organisation in Ants

Sociality in animals is the highest level in the hierarchy of biological organisation. Sociality in animals has advanced furthest in social insects. Hence, colonies of social insects are considered to be eusocial or truly social. Division of labour is the fundamental concept through which the mechanisms underlying the transition to eusociality, both in terms of proximate and ultimate causation, are best addressed. In terms of ultimate causation (evolutionary history), division of labour begins between reproductive and non-reproductive tasks. In social insect colonies division of labour has advanced to the next stage, that is within the non-reproductive tasks such as, for example, brood care, building or foraging. According to Hamilton's rule, for eusociality in ants to evolve division of labour among non-reproductive tasks needs to be effective enough to maximise the production of young and make it cost effective for those individuals who have forfeited direct reproduction to raise the progeny of their relatives. Indeed, as E. O. Wilson once pointed out, a colony of ants is like a 'factory within a fortress'. In other words an ant colony is a superbly designed organisation for the production of young. The fundamental issue here is how this is achieved. Individual ants can perceive only local conditions. No one is in charge and no one oversees the global situation, to plan and to give orders. How can populations of workers be effectively allocated to populations of tasks in such a concurrent, decentralised social organisation?

The approach taken in addressing this issue involves self-organisation theory and its associated bottom-up modelling, that is modelling of collective structures and processes from individual rules of behaviour. My approach has been to test hypotheses about such rules of individual behaviour empirically in the context of the whole colony where all workers are made individually recognisable.

Goals

To understand the principles of concurrent decentralised organisation that have allowed ant colonies to fulfil their function with wide ecological success under natural selection.

Research Projects

• Defying the rules: how self-regulatory social systems work (EPSRC, 2007-2010)

A multidisciplinary project on self-regulation in complex systems with collaborators Professor Kim Christensen and Dr Elsa Arcaute (Physics, Imperial College, London), Dr Angela Espinosa (Business School, University of Hull) and Dr Torbjorn Dahl (Robotics, University of Wales, Newport)

• The collective intelligence of movement in ants (Leverhulme Trust Research Fellowship, 2006-2007)

"Social insect colonies are intelligent in a different way than we are. They find solutions by meshing with the problem. This entails a predicament brains do not have to solve. Ants are mobile. How do they avoid gridlock? A group of more than three mobile robots cannot accomplish a task because of mutual interference. How do tens of ants do it? I investigate experimentally how ants move inside their nests and test hypotheses related to labour division and colony size. Results will facilitate our understanding of collective intelligence and apply to Artificial Intelligence and Collective Robotics."

• Information networks in ant colonies - with Dr Richard James and Rebecca Hayward (Physics, University of Bath), Professor Nigel Franks (Biology, University of Bristol), Professor Nicholas Britton (Mathematics, University of Bath), Dr Robert Planque (Mathematics, Free University, Amsterdam).

• Brood sorting: EPSRC-funded project, 2001-2004, on the interface with minimalist collective robotics, with Professor Chris Melhuish, UWE, Bristol; more recently continuing to work on trying to understand the underlying phenomenon through modelling with Dr Elsa Arcaute, Professor Kim Christensen (Physics, Imperial College, London) and Professer Henrik Jensen (Mathematics, Imperial Colleage, London).

• Ant sorting algorithms (Nuffield Foundation, 2001-2003)

• Spatially explicit division of labour
• Temporal division of labour
• Social resilience
• Collective improvement in performance with experience
• Nest building

Ph.D. Students

• Tom Richardson (2007 - 2010, EPSRC-funded, Defying the rules project (see above), with Professor Nigel Franks, University of Bristol)

• Samuel Scholes (2001 - 2005, Brood-sorting in the ant Temnothorax albipennis: from biology to collective robotics, EPSRC-funded, with Professor Chris Melhuish, UWE, Bristol)

• Matthew Wilson (2000 - 2003, Developing metrics for the comparison of sorting and segregation algorithms in a group of minimalist robots, EPSRC-funded, with Professor Chris Melhuish, UWE, Bristol)

• Elizabeth Langridge (1998 - 2006, part-time, The effects of experience on complete ant colonies, with Professor Nigel Franks, University of Bristol)

• Sarah Backen (1996 - 2000, An experimental investigation of task allocation in the ant Leptothorax albipennis, BBSRC-funded, University of Bath, with Professor Nigel Franks)

Advisor to Ph.D Students

• Antony Aleksiev (2003 - 2006, Building behaviour in Temnothorax albipennis, ORS-funded, Supervisor Professor Nigel Franks, University of Bristol)

• Norasmah Basari  (2011 - , Tandem running in Temnothorax albipennis, funded by home country, Supervisor Professor Nigel Franks, University of Bristol)

M.Sc.  Students

• Jan Van lent (2000, Modelling two-dimensional ant sorting, EPSRC-funded, M.Sc. in Machine Learning and Adaptive Computing, UWE, Bristol)

Other Research Students

• Benjamin Wulf and Thomas Klimek (Biomimetics students, University for Applied Sciences, Bremen, Germany, 2006-2007, second-year project on information networks in ant colonies, with Professor Nigel Franks, University of Bristol)

• Benjamin Wulf (Biomimetics student, University for Applied Sciences, Bremen, Germany, 2007-2008, Bachelor's thesis project Collective protection through individual delays, with Professor Nigel Franks, University of Bristol)

• Elizabeth Franklin  (Graduate Environmental Biology student, University of Plymouth, 25 June - 29 July 2008, EPSRC EmergeNET summer studentship project Collective Task Switching in Social Systems, with Tom Richardson and Nigel Franks, University of Bristol)

List of Publications

1. Richardson TO, Christensen K, Franks NR, Jensen HJ & Sendova-Franks AB  'Ants in a labyrinth: a statistical mechanics approach to the division of labour', PLoS One, 6, 2011, e18416 (pdf)

2. Franklin EL, Richardson TO, Sendova-Franks AB, Robinson EJH & Franks NR 'Blinkered teaching: tandem running by visually impaired ants', Behavioral Ecology and Sociobiology, 65, 2011, 569-579

3. Richardson TO,  Christensen K, Franks NR, Jensen HJ & Sendova-Franks AB  'Group dynamics and record signals in the ant Temnothorax albipennis', Journal of the Royal Society Interface, 8, 2011, 518-528

4. Franks NR, Richardson TO, Keir S, Inge SJ, Bartumeus F & Sendova-Franks AB,  'Ant search strategies after interrupted tandem runs', Journal of Experimental Biology, 213, 2010, 1697-1708

5. Richardson TO, Robinson EJH, Christensen K, Jensen HJ, Franks NR & Sendova-Franks AB  'Record dynamics in ants', PLoS One, 5, 2010, e9621 (pdf)

6. Sendova-Franks AB, Hayward RK, Wulf B, Klimek T, James R, Planque´ R, Britton NF & Franks NR 'Emergency networking: famine relief in ant colonies', Animal Behaviour, 79, 2010, 473-485

7. Arcaute E, Christensen K, Sendova-Franks A,  Dahl T, Espinosa A, Jensen HJ 'Division of labour in ant colonies in terms of attractive fields', Ecological Complexity, 6, 2009, 396-402

8. Berghoff  SM, Wurst E, Ebermann E, Sendova-Franks AB, Rettenmeyer CW & Franks NR 'Symbionts of societies that fission: mites as guests or parasites of army ants', Ecological Entomology, 34, 2009, 684-695

9. Robinson EJH, Richardson TO, Sendova-Franks AB, Feineman O & Franks NR 'Radio tagging reveals the roles of corpulence, experience and social information in ant decision making', Behavioral Ecology and Sociobiology, 63, 2009, 627-636

10. Langridge EA, Sendova-Franks AB & Franks NR 'The behaviour of ant transporters at the old and new nests during successive colony emigrations', Behavioral Ecology and Sociobiology, 62, 2008, 1851-1861

11. Franks NR, Hardcastle KA, Collins S, Smith FD, Sullivan KME, Robinson EJH & Sendova-Franks AB,  'Can ant colonies choose a far-and-away better nest over an in-the-way poor one ', Animal Behaviour, 76, 2008, 323-334

12. Aleksiev AS, Longdon, B, Christmas MJ, Sendova-Franks AB & Franks NR 'Individual and collective choice: parallel prospecting and mining in ants', Naturwissenschaften, 95, 2008, 301-305

13. Langridge EA, Sendova-Franks AB & Franks NR 'How experienced individuals contribute to an improvement in collective performance in ants', Behavioral Ecology and Sociobiology, 62, 2008, 447-456

14. Aleksiev AS, Sendova-Franks AB & Franks NR 'Nest 'moutling' in the ant Temnothorax albipennis', Animal Behaviour, 74, 2007, 567-575

15. Aleksiev AS, Longdon, B, Christmas MJ, Sendova-Franks AB & Franks NR 'Individual choice of building material for nest construction by worker ants and the collective outcome for their colony', Animal Behaviour, 74, 2007, 559-566

16. Aleksiev AS, Sendova-Franks AB & Franks NR 'The selection of building material for wall construction by ants', Animal Behaviour, 73, 2007, 779-788

17. Scholes SR, Sendova-Franks AB, Swift ST & Melhuish C 'Ants can sort their brood without a gaseous template', Behavioral Ecology and Sociobiology, 59, 2006, 531-540

18. Melhuish C, Sendova-Franks AB, Scholes S, Horsfield I & Welsby F 'Ant-inspired sorting by robots: the importance of initial clustering', Journal of The Royal Society Interface, 3, 2006, 235-242

19. Sendova-Franks AB A review of 'Ant colony optimization' by M Dorigo and T Stützle. MIT Press, Cambridge, MA, 2004. Connection Science, 18, 2006, 89-91

20. Scholes S, Wilson M, Sendova-Franks AB & Melhuish C 'Comparisons in evolution and engineering: the collective intelligence of sorting', Adaptive Behavior, 12, 2004, 147-159

21. Sendova-Franks AB, Scholes SR, Franks NR & Melhuish C 'Brood sorting by ants: two phases and differential diffusion', Animal Behaviour, 68, 2004, 1095-1106

22. Langridge EA, Franks NR & Sendova-Franks AB 'Improvement in collective performance with experience in ants', Behavioral Ecology and Sociobiology, 56, 2004, 523-529

23. Wilson M, Melhuish C, Sendova-Franks AB & Scholes S  'Algorithms for building annular structures with minimalist robots inspired by brood sorting in ant colonies', Autonomous Robots, 17, 2004, 115-136

24. Franks NR, Britton NF, Sendova-Franks AB, Denny AJ, Soans EL, Brown AP, Cole RE, Havardi RJ, Griffiths CJ & Ellis SR 'Centrifugal waste disposal and the optimization of ant nest craters', Animal Behaviour, 67, 2004, 965-973

25. Sendova-Franks AB & Van lent J 'Random walk models of worker sorting in ant colonies', Journal of Theoretical Biology, 217, 2002, 255-274

26. Sendova-Franks AB, Franks NR & Britton NF 'The role of competition in task switching during colony emigration in the ant Leptothorax albipennis', Animal Behaviour, 63, 2002, 715-725

27. Franks NR, Sendova-Franks AB & Anderson C 'Division of labour within teams of New World and Old World army ants', Animal Behaviour, 62, 2001, 635-642

28. Melhuish C, Wilson M & Sendova-Franks AB 'Patch-sorting: multiobject clustering using minimalist robots', Lecture Notes in Computer Science, 2159, 2001, 543-552

29. Backen SJ, Sendova-Franks AB & Franks NR 'Testing the limits of social resilience in ant colonies', Behavioral Ecology and Sociobiology, 48, 2000, 125-131

30. Franks NR & Sendova-Franks AB 'Queen transport during ant colony emigration: a group-level adaptive behavior', Behavioral Ecology, 11, 2000, 315-318

31. Sendova-Franks AB & Franks NR 'Self-assembly, self-organization and division of labour', Philosophical Transactions of the Royal Society of London B, 354, 1999, 1395-1405

32. Franks NR, Sendova-Franks AB, Simmons J & Mogie M 'Convergent evolution, super-efficient teams and tempo in Old and New World army ants', Proceedings of the Royal Society of London B, 266, 1999, 1697-1701

33. Franks NR, Tofts C & Sendova-Franks AB 'Studies of the division of labour: neither physics nor stamp collecting', Animal Behaviour, 53, 1997, 219-224

34. Sendova-Franks AB & Franks NR 'Division of labour in a crisis: task allocation during colony emigration in the ant Leptothorax unifasciatus (Latr.)', Behavioral Ecology and Sociobiology, 36, 1995, 269-282

35. Sendova-Franks AB & Franks NR 'Spatial relationships within nests of the ant Leptothorax unifasciatus (Latr.) and their implications for the division of labour', Animal Behaviour, 50, 1995, 121-136

36. Sendova-Franks AB & Franks NR 'Demonstrating new social interactions in ant colonies through randomisation tests: separating seeing from believing', Animal Behaviour, 50, 1995, 1683-1696

37. Sendova-Franks AB & Franks NR 'Social resilience in individual worker ants and its role in division of labour', Proceedings of the Royal Society of London, B, 256, 1994, 305-309

38. Sendova-Franks AB 'Who's who of tramp ants. A review of "Exotic ants; Biology, impact, and control of introduced species" Editor, DF Williams. Westview Press, Boulder. Trends in Ecology and Evolution, 9, 1994, 497-498

39. Sendova-Franks A & Franks NR 'Task allocation in ant colonies within variable environments. (A study of temporal polyethism: experimental)', Bulletin of Mathematical Biology, 55, 1993, 75-96

40. Franks NR & Sendova-Franks AB 'Brood sorting by ants: distributing the workload over the work-surface', Behavioural Ecology and Sociobiology, 30, 1992, 109-123

41. Franks NR, Sendova-Franks AB, Sendova-Vassileva M & Vassilev L 'Nuptial flights and calling behaviour in the ant Leptothorax acervorum (Fabr.)' Insect Sociaux, 38, 1991, 327-330

42. Deneubourg JL, Goss S, Franks N, Sendova-Franks A, Detrain C & Chretien L 'The dynamics of collective sorting: robot-like ants and ant-like robots. In: Meyer J-A, Wilson S (Editors) "Simulation of animal behaviour: from animals to animats" 1991, MIT Press, Cambridge, MA, 356-365

43. Vassilev IB & Sendova AB 'The effect of temperature and pressure on the vitality of certain insects' Comptes Rendus de'Acad. Bulg. des Sciences, 41, 1988, 127-129

A laboratory nest of a Temnothorax (formerly known as Leptothorax) ant colony made of two microscope slides separated by four 1 mm thick cardboard pillars, one pillar in each corner. Such artificial nests have two major advantages. First, they closely approximate the rock crevices these ant colonies utilise as nest sites in nature. Second, they allow us to observe all the individuals all the time. The blue dots are coloured sand blocks from a pile provided outside the nest that the ants have used to build a perimeter wall.