Hippo teeths are sparse, there are fangs on the lower jaw that do not have roots and grow throughout life. The longest hippo tusk was 65.5 cm, and they are even more valued than elephants. Teeth are covered with a hard yellowish plaque.
The hippo’s mouth is unique: he can open it so that the angle between the jaws is about 150 degrees.
Hippos are active mainly at night, when their tender skin is not exposed to ultraviolet radiation, does not dry and does not crack. During the day they doze on the shoals and scythes, at night they go out to graze.
Each hippo has its own pasture patch, which it marks with its droppings, and also marks the entire path, trampled from the reservoir to the pasture.