A hippo's body is perfectly designed for water life. Its eyes, ears, and nostrils are all at the top of its head, so it can float with almost its whole body under the surface while still being able to see, hear, and breathe. It can also close its nostrils completely and hold its breath for up to five minutes when it dives to the river bottom.
Hippos have a special trick to protect their skin from the hot African sun: their skin produces a natural reddish oily liquid that works like a built-in suncream. This liquid also has antibacterial properties, helping small cuts heal quickly. Scientists only discovered this in the early 2000s, so hippos taught us something new about biology not very long ago.
Even though they spend the day in water, hippos are grazers — they eat grass. Each night they leave the river and walk several kilometres in the dark, grazing on riverside grassland, before returning to the water before sunrise. Their wide mouths and large flat teeth are designed for tearing up grass rather than catching prey.