A hippo can weigh as much as 3,500 kilograms — roughly the same as three small cars. Despite their enormous size, they are surprisingly graceful in the water. Their legs act like springs, letting them bounce along the riverbed in slow motion. They can hold their breath underwater for up to five minutes.
Hippos have special skin that oozes a pinkish oily liquid. For a long time people thought this was sweat, but scientists discovered it is actually a natural sunscreen and antiseptic — it protects hippo skin from sunburn and infection. Nature invented sunscreen long before we did.
In the evening, hippos leave the water and walk inland to graze on grass. They can travel several kilometres each night and eat around 40 kilograms of grass — that is roughly the weight of a seven-year-old child. They return to the water before sunrise, which is why you mostly see hippos relaxing in the lake during the day.