How velvet worms slime their prey

A slime jet may not be the most elegant weapon. But velvet worms use slime jets to create a sticky web for snaring prey and deterring predators. These tropical worms aren’t the only organisms to project oscillating slime, but unlike spitting cobras or spiders, the worms keep their head stoically still while spewing slime back and forth. So how does the jet move?

Two things keep the slime stream unstable: the inertia of liquid and the natural elasticity of the tube that projects it, researchers report March 17 in Nature Communications. Based on high-speed video and simulations with plastic tubes, researchers found that the force of the rapidly moving slime causes the tube and, thus the jet, to wiggle back and forth — not unlike an untethered garden hose.