Moorfrog (rana arvalis) in the Engbertdijksvenen, The Netherlands. During the mating season, which last for just a few days, the male moorfrogs turn blue. This process starts at the eyelids. This one blinked with its eyes, which goes one at a time. I captured this when the blue eyelid of the right eye (left for the viewer) was halfway down, which makes it extra cute.