H091
Mosquitoes kill hundreds of thousands of people a year. Sharks kill a handful. Which is more dangerous?
Both charts below use real numbers, and they rank the animals in opposite order. "Most dangerous" can mean two different questions: how many people it kills in total, or how likely one encounter is to kill you.
Two true answers
Question 1: How many people does it kill?
Deaths per year, worldwide
Question 2: If it gets you, how likely is it to kill you?
Share of bites or infections that end in death
"Most dangerous" is two different questions wearing the same words. Mosquitoes kill by far the most people because they bite billions of times a year, even though any single bite is very unlikely to kill. Sharks almost never meet people, but when one bites, it's far more likely to be fatal. Both rankings are true; they answer different questions.
The same switch happens with cars and planes, common and rare diseases, or big and small risks at work: total harm and risk per encounter can point in opposite directions. Before trusting a "most dangerous" ranking, ask whether it counts total deaths or the odds for one person.
Try it somewhere else
A plane crash is far more likely than a car crash to kill the people on board.
Which kills more Americans each year, and which question matters for your trip?
The numbers behind both charts
| Animal | Encounters per year | Deaths per year | Share fatal |
|---|---|---|---|
| Mosquitoes (malaria) | 282 million malaria cases (2024) | 610,000 | 0.2% |
| Humans (homicide) | – | 458,000 (2021) | – |
| Snakes | about 5.4 million bites | 81,410 to 137,880 | 1.5% to 2.6% |
| Dogs (rabies) | – | about 44,000 | – |
| Sharks | 47 unprovoked bites (2024) | 4 | 8.5% |
Malaria is only one of the diseases mosquitoes spread; dengue and others add more deaths. Almost all rabies deaths (99%) come from dog bites or scratches. The shark figure is based on very few bites, so it jumps around from year to year.
Related exhibits
Sources: World Health Organization fact sheets on malaria (2024 estimates), snakebite envenoming, and rabies (2021 Global Health Estimates); UNODC, Global Study on Homicide 2023 (2021 data); Florida Museum of Natural History, International Shark Attack File, 2024 worldwide summary.