How honeybees perceive and traverse apertures

The ability to fly through openings in vegetation allows insects such as bees to access otherwise unreachable food sources. The specific visual strategies employed by flying insects during aperture negotiation tasks remain unknown. In this study, we investigated the visual and geometric parameters of apertures that influence traversing honeybees. We recorded honeybees flying through apertures with varying shapes and sizes using high-speed cameras to examine their spatial distribution patterns and trajectories during passage. Our results reveal that the flight of bees was, on average, along the bilateral center of the edges of the aperture irrespective of the size. When apertures were smaller, bees tended to also fly closer to the vertical center. However, for larger apertures, they traversed at lower vertical positions (closer to the bottom edge). The behaviors suggest that honeybees modulate their flight trajectories in response to spatial constraints, adjusting trajectory relative to aperture dimensions. When entering at off-center horizontal positions, bees tended to access the vertical center of the aperture, indicating altitude selection influenced by the curvature of the edge below. This behavior suggests an acute awareness of the vertical and horizontal spatial constraints and a preference for maintaining a curvature-dependent altitude that optimizes safe passage. Our analysis reveals that honeybees modulate speed and altitude above the ventral edge passing beneath them, maintaining a ventral optic flow magnitude within a preferred range. This relationship suggests a control mechanism where bees rely on visual information in a narrow ventrally directed field to navigate safely through confined spaces.