Figure 2.
Graphical representation of equations (3.9)–(3.11), showing how local packing fraction is obtained through behavioural pressure. At low Ta, bees on the mantle will pack at ρ = ρmax (upper circle), and behavioural pressure is high throughout the cluster leading to higher interior packing fraction (upper solid line) and overpacking. At high Ta, bees on the mantle will pack more loosely (lower circle), and low behavioural pressure throughout the cluster leads to low interior packing fraction (lower solid line). The solid lines run along contour lines of equal Pb(ρ,T), as behavioural pressure must be uniform through the cluster. Coefficients used are ρ0 = 0.85, αbee = 0.75, ρmax = 0.8, χ = 0.3. (Online version in colour.)