You thought humans had invented interlocking gears. Tell that to the planthopper Issus coeleoptratus. Here's an extreme close-up of the insect's nether regions.
Gears on an insect's leg, as viewed from below. Credit: Malcolm Burrows
A close-up of the planthopper’s gears. Credit: Malcolm Burrows
You can see the gears in action below:
To find out how they use these gears (hint, these insects are called planthoppers) check out Ed Yong's post at Not Exactly Rocket Science.