Opinion: Animal killers of human beings

When I saw a question posed: “What animal is the greatest killer of human beings?” My knee-jerk reaction was other human beings. I suppose that I thought about the number of murders that occur in the U.S. annually and extrapolated that to the rest of the world. But that is the kind of assumption and statistical error that a sociologist, like me, should not make. Truly, I know better, but that did not prevent my all-too-human initial reaction.

However, it’s not really a bad answer. In fact, “other human beings” is second on the list and accounts for a bit more than one-third of all people who are killed by other animals. But our murder skills are outshined by a creature that is so tiny that it can be eliminated with just the flick of the little finger. And I’m not writing about a virus or bacterium. I’m writing about something that we can easily see and identify. Have you taken a guess yet?

Human killers

Generally, human beings kill each other with bombs, guns, knives, blunt instruments, poison, or some type of strong-arm tactics. But in other parts of the world, people die from poor sanitation, lack of vaccinations, and the existence of other conditions that make them susceptible to morbid diseases, many of which we had wiped out in our country. Measles, of course, is a disease that’s reappearing since a changing of the guard at the Centers for Disease Control and Prevention (CDC).

According to Hannah Ritchie and Fiona Sooner, writing for Our World in Data, animals kill about one and a half million people each year. More than half of those deaths are directly attributed to our most dangerous enemy, the mosquito. Ritchie and Sooner write, “The biggest killers, by far, are mosquitoes. They have been one of our biggest threats for millennia and still kill approximately 760,000 people every year.” In particular, the 

Anopheles mosquito is the culprit which spreads malaria among the people it attacks for a sip of their blood. And of those 760,000 deaths due to malaria, 500,000 occur among children annually.

The authors point out, “Another 100,000 people die every year from other mosquito diseases, including dengue fever and yellow fever (spread by the mosquito species Aedes aegypti) and Japanese encephalitis.”

Snakes, etc.

Snakes come in third, accounting for approximately 100,000 deaths per year. The article appearing in Our World in Data states, “Snakes are one of the most common phobias, and you can see why.” Their “kill rate” comes right after mosquitoes and human beings. Most snake bites can be treated medically, but the problem is that they often occur in wilderness and rural areas where access to medical personnel and antivenom serum is not readily available. So, death from snake bite may not always be reported, and records are poor. Nevertheless, Ritchie and Sooner state that “the figure is likely to be around 100,000 deaths per year. That means that snakes kill more than all animals below them on the list, combined.” 

Of the remaining species on the Our World in Data list, dogs are the next culprits. Although dogs have been domesticated over the years and have become “man’s best friend,” they kill about 40,000 people each year. It’s unusual that a “direct wound” is identified as the cause of death. In the majority of fatalities, the demise of the victims is due to rabies.

Almost unbelievably, the fifth most dangerous of the various species is the freshwater snail. According to Laura Young, writing for The Institute for Environmental Research and Education, freshwater snails, seemingly innocuous creatures, aren’t dangerous, in and of themselves. Rather, they “serve as crucial hosts for various parasitic worms, notably schistosomes, which cause schistosomiasis.” If left untreated, schistosomiasis can cause liver failure, kidney failure, bladder cancer, and pulmonary hypertension, all of which may result in death. In 2024, 14,000 deaths were attributed to schistosomiasis that resulted from contact with freshwater snails.

The kiss of death

Writing for WebMD, Lori M. King and Alicia Racelis point out, “Kissing bugs are a group of blood-feeding bugs that may “kiss” you on your face around your mouth, usually while you sleep.” Some, though not all, kissing bugs carry a parasite called Trypanosoma cruzi, a carrier of Chagas disease (CD). According to the Mayo Clinic website, CD is easily treated in its early stages. But people who have CD for a long period of time may experience heart or digestive problems that can lead to death. In 2024, 8,000 people died from the “kiss” of these bugs that can be found mainly in the southwestern U.S., Central America, and South America.

On our list of killers of human beings, sandflies come next, followed by roundworms, scorpions, and tsetse flies, which carry “sleeping sickness.” At this point, you may be wondering where some of the most fearsome-looking animals are on the list.

Big cats, like lions, tigers, cheetahs, etc., come in fourteenth. They kill about 300 people throughout the world, annually. They are followed by crocodiles which are credited with only half as many human victims. Hippopotomuses, for all their bad press, kill fewer than 50 people per year. Personally, I am morbidly afraid of bears, possibly because I once escaped a near contact with one while playing golf at Pine Mountain Club in a remote section of the mountains that divide the central valley from the Los Angeles basin. But bears kill only 20 people annually. That doesn’t sound like much unless you’ve nearly been one of them. And sharks, which make the TV news probably more than any other killer species, killed a mere 5 people in 2024.

To my surprise, jellyfish came in sixteenth on the list of 21 animal killers. I’d been stung dozens of times by jellyfish, always when I was younger than 14. We kids would just rub some mud on the sting site, get our fishing nets, and throw the gelatinous creatures up on the beach where they’d shrivel up and die. I guess, to a jellyfish, kids were the most fearsome killers.

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Jim Glynn is Professor Emeritus of Sociology. He may be contacted at j_glynn@att.net.