The hippo is a semi-aquatic animal with imposing dimensions that can be found throughout Sub-Saharan Africa, wherever there is fairly deep water, where it can dive during the day, and surrounded by grasslands, where it can graze during the evening and the night.
During the daytime, hippos spend almost all their time basking in shallow water, their skin, not covered with hair, is very sensitive and must be kept hydrated and protected to avoid sunburn due to sun exposure.
Thanks to the particular position in which the eyes, ears and nostrils are located, exactly placed on the top of the head, hippos can hear, see and breathe while almost the whole of their body is underwater.
To avoid dehydration and scalding of the skin, when not immersed in water, hippos secrete a sort of pink or reddish gel that is produced by the glands that are located right under the skin; this substance helps to keep the skin soft and elastic and protects it from the sun, a sort of natural sunscreen.
Hippos fight frequently, especially male specimens, and often these struggles leave ugly, sometimes bleeding wounds on their bodies; the mucous membrane they secrete also has antibiotic properties that helps prevent infections resulting from wounds.
So the hippos stay in the water during the day to avoid dehydration and sunburn, but in the evening, after the hot sun has set, the hippos come out of the water and spend the night grazing, looking for fresh grass.
Despite their enormous weight, hippos eat on average only 40 kilograms of food per night, a very small amount compared to their weight and the amount of food that other herbivores ingest, such as elephants, for example.
The aquatic and idle life they lead allows them to save a lot of energy, moving their huge body mass into water requires less energy than similar movements on land.
Hippos prefer to feed on grass that grows near rivers and lakes, but, if forced by drought, they can move away from the water and travel up to 10 kilometers each day in search of food.
Hippos graze and eat only on the ground, they prefer short grass, small shoots and green canes, they tend to avoid the coarser herbs that are more difficult to digest, they tear the grass with their very wide lips and chew it with the molars, placed in the back of the mouth.
On the other hand, they do not eat while they are in the water because, chewing, they would ingest too much water.
The long canines and incisors, that continue to grow throughout the life of the animal reaching up to 50 centimeters, have no role in the feeding of the hippo, they are useful means of defense and offense that are used during the fights for mating or to defend against predators.
Although hippos spend almost 16 hours a day immersed in water, they can't swim and can't even float!
Their bodies are too dense to float and their physical characteristics are not suitable for swimming, they move therefore walking on the bottom of lakes and rivers while keeping their nostrils out of the water surface to be able to breathe.
Hippos can also hold their breath for about 5 minutes when they are immersed, but then they are forced to return to the surface to breathe.