Fish never blink, but virtually all land vertebrates do, from salamanders to turtles to us. Scientists have set out to determine why blinking evolved and whether it was directly related to our move to land. To figure out the likely origins of blinking, researchers stared into the eyes of mud skippers, a little fish that spends a lot of time on land. These charming amphibious fishes bloop their eyes down into their heads while a membrane simultaneously sweeps upward. Not only do they blink to avoid potential injury, a single blink clears their eyes of essentially all fine debris. Also, they blink to keep their eyes moist, likely spreading mucous secretions from their head over their eyes since they don’t have tear glands. If conditions get too dry, they adorably roll around in the water to spread it over their eyes.