Males have been known to kill the young, and for this reason, females will herd the little the little ones into the water in order to protect them whenever males come near.
Hippo's canine teeth are considered finer ivory than elephant tusks and they have been widely hunted for this reason.
Their name is derived from the Greek word meaning "river horse".
A single calf is born at a time, weighing approximately thirty kilograms, and are capable of swimming a few moments after birth.
If they are out of the water and in the sun for a long period of time, their skin cracks and glands at the surface of the skin exudes a liquid which looks like blood.
Hippopotamus have the thickest skin of all land mammals - five centimetres - which constitutes a large percentage of their total body weight.
Certain fish will eat hippo dung. In some African countries, the people will use this to bait their fish traps.