This Is Why Red-Eyed Tree Frogs Have Red Eyes

red-eyed tree frog. Jaymi Heimbuch

Red-eyed tree frogs spend most of their time trying to blend in. During they day, they stay tucked in the undersides of leaves, trying to catch some sleep. With their legs pulled in tight and their eyes closed, they look like little more than a vague, green blotch. But should a predator still notice them, these frogs can use their shocking color scheme to their advantage.

National Geographic explains:

When disturbed, they flash their bulging red eyes and reveal their huge, webbed orange feet and bright blue-and-yellow flanks. This technique, called startle coloration, may give a bird or snake pause, offering a precious instant for the frog to spring to safety.

If you thought you were snagging a boring green frog for a meal and suddenly came face to face with deep red eyes and bright blue legs, you might think twice about whether or not this would be a safe meal — especially if you live in a habitat where brightly colored markings usually warn potential predators of an animal's toxicity. While the red-eyed tree frog is not toxic, that flash of color is enough to startle a predator or make it second guess its choice, giving the frog that split-second it needs to escape.