What creatures pose the greatest danger to humans?
No contest: not snakes, not octopuses, but flies. And among flies, mosquitos are the deadliest. By itself, the malarial parasite carried by mosquitos probably kills a million people a year in Africa alone. Over the course of history, malarial protozoa may have killed more people than all the wars ever fought. Mosquitos also carry yellow fever and at least 100 different viruses. Altogether, these diseases make at least 300 million people sick every year. As for houseflies, just one can carry as many as 6 million disease-causing bacteria. Many of the germs hitch rides on the fly’s hairy body and sticky foot pads. Its digestive tract carries far more. The latter often emerge to begin their own colonies as a result of the fly’s habit of dissolving its food by vomiting on it. Aggravating matters is the fly’s sheer plenitude and its tendency to keep moving, often in an unhygienic commute between animal wastes and human food. Flies have been considered a source of pestilence since antiquity.
