When mechanochromic photonic crystals are stretched or compressed, their nanoscale structure deforms, changing the spacing between layers and shifting the reflected light wavelength. This causes a visible color change, which is useful for visual strain se interestingasfuck
βA David vs. Goliath Moment. Not sure was type of spider this is, but it has its hand full with this Oriental Latrine Fly (Chrysomya megacephala) spiders