They show aggression towards crocodiles living in the same water bodies, especially when young hippos are around. Attacks on humans also occur, although there are no reliable statistics. It is reported that about 500 people are killed yearly in clashes with hippos. However, this information travels from village to village without verifying the true causes of death. It is also rare for hippos to kill each other. When males clash, the fight ends with one recognizing the superiority of its opponent. It also happens that males try to kill the offspring or females try to kill a male in defense of the young - this happens only when food is scarce or the area occupied by the herd is shrinking.
