Gyrinidae

Gyrinidae, commonly known as whirligig beetles, is a family of water beetles in the order Coleoptera that usually swim on the water surface but dive underwater when threatened, taking their common name from their habit of swimming rapidly in circles when alarmed. The family includes about 700 living species in 15 genera, plus a few known only as fossils, and its divided eyes are thought to let it see both above and below the waterline at once. Most species are similar in general appearance, ranging from about 3 to 18 millimeters long, with flattened, rounded, ellipsoid bodies and legs fitted closely to a streamlined profile. This description is adapted from Wikipedia contributors under CC BY-SA 4.0; changes were made. https://creativecommons.org/licenses/by-sa/4.0/