Reader Stephen Barnard, occupier of Paradise in Idaho, called my attention to a new article in Science which, sadly, I don’t have time to read (I’m off to Cracow in an hour or so). But it reports that the nymphs of an “issus” (a genus of planthopper on the order Hemiptera, or “true bugs”) have gears on their legs: the first example of a cog-like mechanism in animals. I’ll give the abstract and then show a YouTube video that will tell you how the gears look and work.

Here’s the paper’s abstract:

Gears are found rarely in animals and have never been reported to intermesh and rotate functionally like mechanical gears. We now demonstrate functional gears in the ballistic jumping movements of the flightless planthopper insect Issus. The nymphs, but not adults, have a row of cuticular gear (cog) teeth around the curved medial surfaces of their two…