Watch as we take you deep into the heart of the night, where the most dangerous and elusive animals emerge. As the sun sets ...

The hippo may appear gentle, but it ranks high among deadliest animals due to its territorial nature and immense strength.

The opposite is also true. In the 19th century, European cattle brought rinderpest—a virus that’s nearly always fatal to hoofed animals—to Africa, and it caused buffalo numbers to crash ...

Analysis - Compared with Africa's other big animals, hippos have been relatively neglected in scientific research. Partly, this is because they're hard to study and dangerous to encounter.