As we read in the message Pliny the Elder, the Egyptian Nile River gives birth to large creatures, among whom he lists hippos. According to the Roman researcher, the skin of the animal is very durable and is used to create shields and helmets. However, when the skin is properly soaked, its durability decreases.
Pliny claims that hippos eat grain, and they enter the field backwards, so that, in the event of an ambush, they may be able to quickly escape.
Another interesting piece of information given by the Roman is the “fact” that hippos can drain blood from their veins by themselves. Thus, when an animal becomes too bulky and heavy, it descends to the river bank, where it searches for a sharp enough reed to prick it with a thigh and pierce a vein. After the blood is drained, the body relaxes and the hippo covers the wound with mud.