These caterpillars in the Amazon rain forest travel together in kind of a treadmill formation, with the whole group able to travel faster than any individual caterpillar.
Here's the explanation. And I've got a thing for treadmills, I guess: here's the plane on a treadmill problem, Slinky on a treadmill, and a Japanese game show featuring treadmills. (via @stevenstrogatz)
