Many animals wear drab colors: browns and greens that closely match their surroundings. This type of coloration, called camouflage, helps a creature to blend in, to go unnoticed. A lizard is far less likely to see a leaf-green katydid sitting on a plant stem than a bright orange monarch butterfly. However, if given a choice between the two, it would be an unwise lizard that chose the butterfly for its next meal.

Monarch butterflies and other brightly colored creatures use flashy threats instead of camouflage to avoid being eaten. Often these threats are backed up by bad smells, bad flavors, painful bites or stings, or a harmful poison. Monarchs, for example, carry a poison inside their bodies that they obtain from the milkweed they eat as larvae. Coral snakes have poison, too, but theirs is delivered through a painful, and potentially deadly, bite. Although animals with such bold coloration tend to stand out like sore thumbs, predators tend to avoid them, especially if they have had a distasteful or painful experience with a similar-looking animal in the past.

The same bright colors that ward off danger also help animals attract mates. Peacocks are famous for their long, beautiful, iridescent green and blue tail feathers and for the audacious Las Vegas-style courtship displays they put on whenever a peahen strolls by. It turns out that there's a reason for all this pomp and circumstance, no matter how unimpressed a peahen may appear in response to such a display. Studies have shown definitively that males with the longest tails and most impressive displays have more success attracting mates and ultimately produce more offspring. And this is the case with countless creatures around the world, including many other birds, fish, reptiles, amphibians, mammals, and invertebrates. After all, the louder the message, the better it's heard.