In 2015, a team of researchers from Tsinghua University in Beijing used a high-speed camera to observe how honey bees curl their abdomens while in flight and under restraint, confirming that bees can manipulate the shape of their abdomens, but only in one direction -- down, toward the bee's underside.
Now the same team has identified the mechanism behind that movement. Specialized membranes that connect a honey bee's abdominal segments are thicker on the top of the abdomen than on the bottom, allowing curling in just one direction.
Honey bee abdomens contain up to nine overlapping segments that are similar to little armored plates. A thin, flexible layer of cells called the folded intersegmental membrane (FIM) connects the tough outer plates, allowing each concentric segment not just to attach to its neighbor, but to slide into the next one. The authors call this movement "telescoping."