Sharing this Red bellied woodpecker image to illustrate an unusual adaptatio

Sharing this Red bellied woodpecker image to illustrate an unusual adaptation they have. In addition to upper & lower eyelids, all woodpeckers have a third eyelid, called the nictitating membrane. It is translucent. This nictitating membrane protects their eyes from debris as they excavate trees for tasty grubs. Also used for a quick nap, as is this image.
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