(A) The homing behaviours to be produced by the model when displaced either from the nest and having no remaining PI home vector (zero vector), or from the nest with a full home vector (full vector). Distinct elemental behaviours are distinguished by coloured path segments, and stripped bands indicate periods where behavioural data suggests that multiple strategies are combined. Note that this colour coding of behaviour is maintained throughout the remaining figures to help the reader map function to brain region. (B) The proposed conceptual model of the insect navigation toolkit from sensory input to motor output. Three elemental guidance systems are modelled in this paper: path integration (PI), visual homing (VH) and route following (RF). Their outputs must then be coordinated in an optimal manner appropriate to the context before finally outputting steering command. (C) The unified navigation model maps the elemental guidance systems to distinct processing pathways: RF: OL - > AOTU - > BU - > CX; VH: OL - > MB - > SMP - > CX; PI: OL - > AOTU - > BU - > CX. The outputs are then optimally integrated in the proposed ring attractor networks of the FB in CX to generate a single motor steering command. Connections are shown only for the left brain hemisphere for ease of visualisation but in practice are mirrored on both hemispheres. Hypothesised or assumed pathways are indicated by dashed lines whereas neuroanatomically supported pathways are shown by solid lines (a convention maintained throughout all figures). OL: optic lobe, AOTU: anterior optic tubercle, CX: central complex, PB: protocerebrum bridge, FB: fan-shape body (or CBU: central body upper), EB: ellipsoid body (or CBL: central body lower), MB: mushroom body, SMP: superior medial protocerebrum, BU: bulb. Images of the brain regions are adapted from the insect brain database https://www.insectbraindb.org.