Did you Know? Hippos can’t swim.

Hippos can’t swim. Hippos really do have big bones, so big and dense, in fact, that they’re barely buoyant at all. They don’t swim and instead perform a slow-motion gallop on the riverbed or on the sea floor. In fact, hippos can even sleep underwater, thanks to a built-in reflex that allows them to bob up, take a breath, and sink back down without waking.