“What’s this shiny black beetle with four eyes?” asked Erin Hayes-Pontius, a visiting UVM student, from her microscope. Without glancing up from my own scope I answered, “that’s a whirligig beetle.” Erin’s answer came back: “err, cute … but what’s it really called?”

I will grant you that the name whirligig is a bit odd – particularly when applied to an inert pickled beetle – but there are excellent reasons it. In life, whirligig beetles weave and whirl on pond and river surfaces amongst dozens of their peers. They move like miniature motor boats that appear to lack rudder function. There’s method to this seeming madness. The mesmerizing movement confuses predators, who find it difficult to focus on any one individual. Ecologists call this phenomenon predator dilution. It’s like the old joke about the two friends and the tiger: “I don’t need to outrun the tiger, I just need to outrun you!” » Continue Reading.