I'm cheating a bit with this one, since there are actually something around the ballpark of 15,000 species in the Buprestidae family, but hey, they are a really interesting group of insects! They range in size (from about 4-100mm) and habitat, but they all share the common characteristic of looking shiny.
Scientists have been looking at the molecular structure of their every so shiny exoskeletons because they reflect, rather than absorb color.
One specific species, the jewel scarab Chrysina gloriosa, can actually distinguish between circularly polarized and non polarized light, and reflect circularly polarized light off of their exoskeletons. This allows them to see each other, but keeps predators from seeing them. Only one other species (a type of shrimp) is known to be sensitive to this type of light. (CP light is what movies these days are using for 3D effects, we have to wear glasses cause humans lack the natural perception)
And while we're on the topic of super neat exoskeletons, their vibrant colors have led certain cultures to use them for decorative purposes for hundreds of years. You can even buy your own beetle jewelry!
detect fires from dozens of miles away using a sensor that detects infrared radiation from fire and other sources. They specifically need burnt firewood to breed so what better way to figure out where fires are happening? Figuring out how to mimic these sensors could have major civilian and military impacts, and all from the undersides of tiny beetles! (Interestingly, these places are a great place for them to breed because no other critters go there. Safety!)
images from hondurasbutterfly.com and treknature.com