Hippos spend their days partially submerged in the rivers or lakes, sheltering themselves from the hot sun, often remaining in the water for as much as 16 hours a day. At night they come out and forage for grass, eating as much as 80 lbs of grass as they forage over a distance of 6 miles. In spite of their size hippos can move rapidly, especially for short distances when a hippo can run up to 19 miles per hour.
Hippos can be highly aggressive and unpredictable, and reports indicate more people are killed in Africa by hippos than any other animal. A hippo can open its giant jaws to near 180 degrees and the compression power of its clamp can easily break the back of an adult crocodile.
Their lifespan is around 40 to 50 years of age, with two recorded to have lived to be 61 years of age. There are an estimated 125,000 to 148,000 hippos remaining in the world in the wild.