Nacreous Moth And Larval Locomotion

The nettles that we leave uncut in the corner of our field attract lots of insects, including mother-of-pearl moths. I've photographed them in previous years and in the right light they shine just like the inside of an oyster shell. This one was on the underside of a burdock leaf so not showing its iridescence. I was going to wait until I got one in the correct light until I read a fascinating fact about mother-of-pearl moth caterpillars.

One source mentioned that they have a form of locomotion that has inspired the development of next-generation rolling robots. I wanted to know more and found this.  "If the caterpillar meets a predator, it anchors its rear to the ground, recoils rapidly, and then rolls away backward like a bright-green tire. Mouth to tail, it completes around half a dozen revolutions during its escape. By turning into a wheel, the caterpillar moves some 40 times faster than its normal walking pace."