Optimal Collective Decision-Making in Social Insect Colonies

More recent publications and coverage arising from the project are available at the BET Lab pages.

This BBSRC funded, 3-year, £500k project started in August 2009, and is building on ground-breaking work by this team in understanding how collective decision-making by rock ants and honeybees may be organised so that the resulting collective decisions are statistically optimal, representing the best possible compromise between the speed and accuracy of decision-making. The speed-accuracy trade-off in decision-making has been widely recognised in individual organisms, such as humans (Ratcliff, 1978) and bumblebees (Chittka et al., 2003) and in highly cohesive animal societies, particularly ants (Franks et al., 2003) and honeybees (Seeley & Visscher, 2004). Our recent work has been inspired by statistically optimal models of decision-making in primate neural circuits, and has shown how simple models of collective decision-making by social insect colonies can also be parameterised to implement statistically optimal decision-making (Marshall et al., 2009). This synthesis of concepts and techniques from neuroscience and insect socio-biology is one of the first studies in the rapidly emerging field of 'Colony-Level Cognition' (Marshall & Franks, 2009).

The project has experimental and theoretical strands: experiments with rock ants (Bristol) and honeybees (Cornell/Arizona) are evaluating theoretical predictions using state-of-the-art RFID tag technology, and helping inform further modelling.





Recent Media Coverage

  1. 'Ants and Neurons'. SEED Magazine, 23rd July 2009.
  2. 'Six Legs Goods'. Guardian g2 cover feature, 9th March 2009.
  3. 'Human Brain Like Colony of Ants'. Channel4.com, 25th February 2009.


  1. Chittka, L., Dyer, A., Bock, F., Dornhaus, A. (2003) Bees trade off foraging speed for accuracy, Nature 424, 388
  2. Franks, N. R., Dornhaus, A., Fitzsimmons, J. P. & Stevens, M. (2003) Speed versus accuracy in collective decision-making. Proceedings of the Royal Society B: Biological Sciences 270 (1532), 2457 - 2463
  3. Marshall, J. A. R., Bogacz, R., Planué, R., Kovacs, T. & Franks, N. R. (2009) On optimal decision making in brains and social insect colonies. Journal of the Royal Society: Interface (doi: 10.1098/rsif.2008.0511)
  4. Marshall, J. A. R. & Franks, N. R. (2009) Colony-level cognition. Current Biology 19, 10 (in press)
  5. Ratcliff, R. (1978) A theory of memory retrieval. Psychological Review 85, 59-108
  6. Robinson, E. J. H., Smith, F. D., Sullivan, K. M. E. & Franks, N. R. (2009) Do ants make direct comparisons? Proceedings of the Royal Society Series B, (in press)
  7. Seeley, T. D. & Visscher, P. K. (2004) Quorum-sensing during nest-site selection by honeybee swarms. Behavioral Ecology and Sociobiology 56, 594-601
Last modified on August 6th 2010