ScienceNot yet confirmed elsewhere1 publisher2 min readPublished
Honey bee stinger pumps venom with two collapsible pistons, high-speed video shows
Macquarie University researchers used high-speed video to show that a honey bee's 2-millimeter stinger pumps venom with two collapsible pistons. Each lancet carries a valve, and the pair pump in opposite directions to give a continuous flow.
The Scientist · Science desk
Key figures: a gap of at least 116 years between the valves being known and their function being explained; valves known as early as 1910; PNAS paper published in 2026; honey bee stinger roughly 2 millimeters.
| Figure | Value | Note | Claim |
|---|---|---|---|
| Gap before valve function was explained, at least | 116 years | 18 | |
| Valves known as early as | 1,910 year | 4 | |
| PNAS paper published | 2,026 year | 15 | |
| Stinger size, roughly | 2 millimeters | 2 |
What happened
- After a worker bee thrusts its stinger into a target it flies away, a process called autotomy, and the stinger keeps penetrating tissue and injecting venom under its own power.
- Two sharp lancets slide back and forth on rails called the olistheter, like a reciprocating saw, working the stinger deeper into the skin and pumping the venom.
- Researchers from Macquarie and the University of New South Wales had bees sting a clear gel that mimics human skin, and recorded the stinger pumping on its own for the first time.
- On the video the valves inflate like a parachute on the downstroke, acting as pistons on the venom in the chamber, then deflate on the upstroke.
- The team also used microCT scans to 3D-print a scaled-up working model of the bulb chamber and lancets, which confirmed key features of the pumping cycle.
Why it matters
- capability A pump geometry now exists on paper for engineers who need continuous flow from a small unit; the authors propose it as inspiration for micropumps in minimally invasive medical and microfluidic technologies.
- constraint The film comes from a gel that mimics skin, so it shows the pump cycle but cannot show how actual tissue affects it.
- decision Anyone weighing the geometry for a device takes on the trade the lead author describes: the double-piston design adds complexity, and in exchange the stinger delivers venom continuously from a compact, autonomous unit.
The valves have been on record since at least 1910, and for at least 116 years [18] what was missing was how they work. Lead author Dr Fiorella Ramirez-Esquivel of Macquarie University said, "We've known since as early as 1910 that the venom sac of a honey bee stinger empties into a chamber with little pumping elements called valves, but until now we didn't know exactly how they work." [3][4]
The upstroke collapse, according to the researchers, generates pressure for pumping while minimizing backflow during refilling [8]. The last step comes mid-stroke. "Finally, and perhaps most dramatically, as the valves meet in the middle of the stroke, they change shape again to push past each other," Ramirez-Esquivel said [10]. A seal has to hold through that pass. Ramirez-Esquivel said the maneuver is "a remarkable strategy to pump fluid since maintaining a seal is vital to effectively transmit pressure." [11]
In our view the pumping cycle is well supported. Video of the real stinger and a scaled-up model point to the same cycle [9][13].
The account lists muscles and nerves among the stinger's parts [16]. It does not say what drives the lancets in a detached stinger, how those parts set the stroke, or how many stings were filmed.
The account here is Macquarie's own, republished by Phys.org [17]. The paper is "The honey bee stinger: An unusual pump with collapsible double pistons," in PNAS [15].
What to watch
- Whether the PNAS paper or follow-up work says what drives the lancets in a detached stinger and how many stings were filmed.
- Any test of the cycle in real tissue, since the footage so far comes from a skin-mimicking gel.
- A working micropump that copies the collapsible-valve geometry; the only built version in the account is the scaled-up model.
Clarity's read
What the record supports and how the coverage leans. The claims behind it follow.
Reality
- Evidence68
- Adoption
- Insufficient
- Hype gap+10
- Incentives
- Insufficient
- Confidence65
Claim ledger
Ranked by verification strength, evidence, and original report placement.
- [1]
Australian scientists used high-speed video to uncover the mechanism that lets a honey bee's stinger keep pumping venom into its target after it has separated from the bee's body.
- [2]
A study published in PNAS reports that the roughly 2-millimeter stinger of the honey bee (Apis mellifera) works as a double-piston micropump.
- [3]
The lead author of the study is Dr Fiorella Ramirez-Esquivel of Macquarie University.
- [4]
Ramirez-Esquivel said: "We've known since as early as 1910 that the venom sac of a honey bee stinger empties into a chamber with little pumping elements called valves, but until now we didn't know exactly how they work."
- [5]
After a worker bee thrusts its stinger into a target it flies away, leaving the stinger behind in a process called autotomy; the stinger then continues to penetrate the tissue and inject venom under its own power.
- [6]
Researchers from Macquarie and the University of New South Wales had bees sting a clear gel that mimics human skin and recorded video of the stinger's autonomous venom pumping for the first time.
- [7]
The stinger has two sharp, pointed lancets that slide backward and forward on a system of rails called the olistheter, in a motion similar to a reciprocating saw; the lancets work the stinger deeper into the skin and also pump the venom.
- [8]
The valves collapse on the upstroke, generating pressure for pumping while minimizing backflow during refilling, according to the researchers.
- [9]
High-speed video showed that the valves inflate like a parachute on the downstroke, functioning as pistons that apply downward pumping pressure on the venom in the chamber, then deflate on the upstroke.
- [10]
Ramirez-Esquivel said: "Finally, and perhaps most dramatically, as the valves meet in the middle of the stroke, they change shape again to push past each other,"
- [11]
Ramirez-Esquivel said of the valves pushing past each other: "This is a remarkable strategy to pump fluid since maintaining a seal is vital to effectively transmit pressure."
- [12]
Ramirez-Esquivel said the double-piston design adds complexity, but it is the key to the stinger being able to deliver venom continuously in a compact, autonomous unit.
- [13]
The researchers used microCT scans to 3D-print a scaled-up working model of the bulb chamber and lancets to explore the stinger's mechanics and flow, and the model confirmed key features of the pumping cycle.
- [14]
Ramirez-Esquivel said the valves act as collapsible pistons and, by pumping in opposite directions, deliver a continuous flow of venom.
- [15]
The paper is titled "The honey bee stinger: An unusual pump with collapsible double pistons" and was published in Proceedings of the National Academy of Sciences in 2026, DOI 10.1073/pnas.2603916123.
- [16]
The stinger contains several components, including a venom sac and pumping chamber, muscles and nerves.
- [17]
The content was originally published on the Macquarie University Lighthouse and republished by Phys.org.
- [18]
Valves were known since at least 1910 and their function was unexplained until the 2026 paper, a gap of at least 116 years.
- [19]
The study authors conclude that the design principles they uncovered could provide inspiration for engineered micropumps with potential applications in minimally invasive medical and microfluidic technologies.
Sources
1 independent publisher whose own reporting we read for this story.
- phys.orgHigh-speed video reveals how honey bee stingers keep pumping venom after detachment
1 article · October 12, 2026
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