The upward tilt of honeycomb cells increases the carrying capacity of the comb and is not to prevent the outflow of honey

Abstract

The cells of the combs of Apis mellifera are tilted upwards by approximately 13°. The literature says that this tilt serves to prevent the outflow of honey. We checked this by hanging empty honeycombs upside down into beehives. Honey was stored in these inverted honeycombs in the same way as in the normally oriented combs, and inverted combs were also well accepted for rearing the brood. We thus show that the benefit for the bees of the upward tilt of the cells is not to prevent leakage of honey. Honey is obviously in a Wenzel state on the hydrophobic, micro-structured cell walls. The associated wetting of the cell wall causes adhesion that prevents leakage. We propose that the benefit of the inclination of the cells is to direct about 10% of the weight of cell contents onto the midwall, thus increasing the carrying capacity of the comb.