Honeycomb construction on designed foundations reveals geometry-dependent developmental pathways

Honeycomb construction by honeybees is a classical example of collective biological structure formation, yet how ordered cell patterns develop under imposed geometric constraints remains insufficiently understood. Here, we experimentally investigated comb development by introducing 3D-printed designed foundations into an active honeybee colony and comparing conditions that differed in lattice symmetry and scale. The foundations consisted of three hexagonal lattices with nominal across-flats opening sizes of 5.0, 6.7, and 20 mm, and a square lattice with a nominal opening side length of 5.4 mm. On the small and medium hexagonal foundations, construction proceeded through local wax attachment, formation of dome-like protrusions, lateral expansion, and incorporation into a more continuous planar comb. In contrast, on the large hexagonal foundation, wax attachment was localized mainly along the raised lattice walls, and subsequent growth proceeded mainly outward from the foundation surface. On the square foundation, early wax attachment followed the imposed orthogonal boundaries, but this arrangement was not maintained during later development. Initially dominant four-sided cells progressively decreased, whereas five- and six-sided cells increased, indicating a transition from an orthogonal arrangement toward hexagonal-like mixed polygonal configurations. These results suggest that imposed geometry influences developmental pathways and coverage dynamics, while comb organization can progressively evolve toward hexagonal-like structures through local attachment, growth, and subsequent morphological reorganization.