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Golden Tortoise Beetle

Though it looks exceedingly pretty and jewel-like, this little beetle is actually incredibly metal. At just 5 to 8 millimetres long, the Golden Tortoise Beetle (Charidotella sexpunctata) is native to North America, found on plants such as sweet potato and morning glory. But upset one of these little guys and things change very quickly—they are the first known insect species to have the ability to rapidly change colour, not only when agitated but also during copulation (which, according to the very dedicated Edward M. Barrows of Georgetown University, can last anywhere from 15 to 583 minutes). The beetle has been observed to turn a variety of shades, from liquid gold to purplish to greenish gold to brownish to bright red. These colours are produced by an optical illusion: the beetle’s outer cuticle is transparent and it reflects light through a layer of liquid, and the beetles can alter the reflectivity of this liquid by using microscopic valves controlling moisture levels under their shell. Such reversible colour change is extremely rare, especially since the change is controlled: it’s elicited in response to specific events in their environment, whether it’s finding a mate or being annoyed by curious humans. Researchers speculate that it serves some interesting purposes, from defence (perhaps by mimicking ladybugs, which aren’t as tasty to their predators) to sexual signalling to mates. Be warned, though: if you catch one of these beetles, it will quickly turn a dark, dull brown, losing all the brilliant gold it had in life. To finish on an incredibly hardcore note: as larvae, the beetle has a fork-like structure hinged to its rear end, and will stick old skin and their own faeces to it, creating a shield for defence—otherwise known as a faecal parasol. Told you these little guys were metal.

(Image Credit: 1, 2, 3)