Their bodies can overheat easily and need to be cooled in water, which is why they spend most of the day submerged. They swim very well and dive for periods of about three minutes before coming up to breathe noisily. At night, and occasionally on wet overcast days, hippos leave the water to graze the vegetation. Africa Females give birth to a single calf either on land or in the water. The calf is suckled on land for the first few weeks and then in the water.
Mothers are very protective and teach their young to swim and wallow.
As you watch hippos you will most likely hear them grunting and might see them spreading their dung with vigorous wagging movements of their short strong tails. You may notice scars on the backs of the males. These are inflicted by teeth of other males during fights. It is safe to watch the hippos from the bank as they bask in the water, but they should be avoided if found on land. Hippos are usually placid creatures but can become very aggressive if an intruder gets between them and their pool.