American
Dipper

They can dive up to 20 feet deep and use their half-open wings to "fly" or walk along the rocky bottoms of fast-moving streams to hunt for insect larvae.

They have special clear second eyelids (nictitating membranes) to help them see underwater, and scaly nasal flaps that close their nostrils so water cannot get in.

They constantly dip or bob their entire bodies up and down (up to once every second) while standing on rocks. Scientists believe this rhythmic movement helps them communicate over the loud noise of rushing water or hide from predators.