Human beings are easily the biggest killers on the planet, killing not only other members of their own species but also of other species. The number of homicides alone is close to 500,000 per year. But what animal is the biggest killer of humans? It turns out that it is the mosquito, causing the deaths of about twice as many people as humans do. But the mosquito is not really the killer, it just serves as a vector for diseases. If one eliminates vector-carriers such a mosquitoes, flies, bugs, snails, and worms, the top four killers are in the order: snakes, dogs, crocodiles, and hippos.
Snakes, with 50,000 annual deaths, are no surprise. I did not expect dogs (25,000), which many of us view as friends of humans, to be second on the list, but I expect that they are there because there are so many of them and they live in close proximity with humans, so even if the probability of being killed by any given dog is very small, the total number can be large. Crocodiles come in third with 1000 and that also make sense, given that they have such a ferocious image.
But the real surprise was the hippo because although the number at 500 is just 1% that of snakes, the image I have is that of a placid animal that spends its time floating lazily in the water or lumbering around on land. One does not think of the hippo as being a dangerous animal, but that is probably because most of us never encounter a hippo in the wild. I will steer clear of them in the future and not try to make friends with them.