High-speed video has revealed how honey bee stingers deliver venom, showing that the valves attached to each lancet change shape as they move. Both valves sit inside the venom-pumping chamber, and as they slide back and forth they inflate like a parachute on the downstroke. This creates a seal through a piston-like action that applies downward pressure in the chamber, pushing venom out. On the upstroke the valves deflate, and when they meet in the middle they reshape again so they can push past each other.
Co-author Fiorella Ramirez-Esquivel of Macquarie University explained that the unique geometry of the valves is key. "They act as collapsible pistons and—by pumping in opposite directions—they're able to deliver a continuous flow of venom," she said. "The double piston design adds complexity, but it's the key to the stinger being able to deliver venom continuously in a compact, autonomous unit." The dual motion also minimizes backflow, a finding consistent with the authors' preliminary flow visualization experiments.
To verify the results, the team used micro-CT scans to build a 3D-printed scaled prototype that mimicked the observed pumping behavior. The artificial model showed the same pumping kinematics as the biological stingers. Future work may examine the valves' material properties, since the team's artificial polymer valve suggested that extremely high elasticity and low friction between the valves are essential. Researchers also want to investigate whether capillary action plays a role given the small size of the venom-pumping elements.
The authors believe the research could lead to medical and microfluidic applications, such as artificial pumps, building on earlier work that used bee stinger structure to inspire microneedles, tissue transport devices, and drilling tools. The study was published in PNAS in 2026.
Source: Ars Technica · Summarized by HeadlinesBriefing