Frog-legged leaf beetles are known for their enlarged hind legs (hence the name), which they use for jumping to escape predators. Speaking of predators, they also employ a pretty eye-catching defense with their shiny bodies. They look metallic because their color isn’t from pigment, but from microscopic structures in their shell. These structures reflect light in a way that creates iridescent colors like green, blue, and gold. It’s called structural coloration, and it’s the same kind of light effect you see in soap bubbles or oil slicks. This can help them slip past a predator’s eye or potentially bluff one with their bright colors. Generally speaking, bright colors in the animal world are often a way of signaling “hey, I might be toxic.” Not toxic like your ex, but more like it’s probably not a good idea to eat.