Shape and dynamics of thermoregulating honey bee clusters

A model of simple algorithmic "agents" acting in a discrete temperature fie ld is used to investigate the movement of individuals in thermoregulating h oney bee (Apis mellifera) clusters. Thermoregulation in over-wintering clus ters is thought to be the result of individual bees attempting to regulate their own body temperatures. At ambient temperatures above 0 degrees C, a c lustering bee will move relative to its neighbours so as to put its local t emperature within some ideal range. The proposed model incorporates this be haviour into an algorithm for bee agents moving on a two-dimensional lattic e. Heat transport on the lattice is modelled by a discrete diffusion proces s. Computer simulation of this model demonstrates qualitative behaviour whi ch agrees with that of real honey bee clusters. In particular, we observe t he formation of both disc- and ring-like cluster shapes. The simulation als o suggests that at lower ambient temperatures, clusters do not always have a stable shape but can oscillate between insulating rings of different size s and densities. (C) 2000 Academic Press.