Deadliest Animals to Humans: Which Cause the Most Deaths?

How are animal deaths counted?

Most of the people on this list do not die from an attack. They die from a disease that an animal carries and passes on, so the “deadliest animals” are mostly small and easy to overlook. Large, famous predators such as sharks, wolves and bears kill very few people.

Every number here is an estimate. Many deaths happen in rural areas without hospitals or death certificates, so official figures can be far too low. In India, for example, a large community study of snakebite deaths in 2005 found more than 30 times as many as the official count. Figures for animals such as hippos and crocodiles rest on scattered reports, not systematic counts. A widely shared 2014 infographic on Bill Gates’ blog popularized this kind of ranking; the figures below use more recent data where they exist.

1. Mosquitoes: hundreds of thousands of deaths a year

Malaria is caused by Plasmodium parasites that are spread by female Anopheles mosquitoes. WHO estimated 610,000 malaria deaths in 2024, up from 598,000 in 2023. About 95% of them occur in Africa, where around three in four malaria deaths are children under 5.

Other mosquitoes spread other diseases. The yellow fever mosquito (Aedes aegypti) carries dengue, Zika, chikungunya and yellow fever, and dengue hit a record of more than 14.6 million reported cases and more than 12,000 reported deaths in 2024. Culex mosquitoes spread West Nile virus, including in Europe and North America. Locally spread dengue has also reached southern Europe, carried by the invasive Asian tiger mosquito (Aedes albopictus).

Only female mosquitoes bite, because they need protein from blood to make eggs. Of the roughly 3,600 mosquito species, only a small fraction spread disease to people.

2. Snakes: about 81,000–138,000 deaths a year

WHO estimates that snakebites kill 81,410–137,880 people each year and leave about three times as many with amputations or other permanent disabilities. Most victims are farmers, herders and children in rural South Asia, sub-Saharan Africa and Southeast Asia. In India alone, a nationwide study estimated about 1.2 million snakebite deaths between 2000 and 2019, an average of about 58,000 a year, mostly caused by Russell’s vipers, saw-scaled vipers, kraits and cobras.

In Europe and North America, deaths are rare. About 7,000–8,000 people are bitten by venomous snakes in the United States each year, and about 5 die. In 2017, WHO added snakebite envenoming to its list of neglected tropical diseases. The famous black mamba is less important than vipers for total deaths; see Is the black mamba the deadliest snake?

Anyone bitten by a snake should seek emergency medical help immediately: call 911 in the US, 112 in the EU or 999 in the UK.

3. Dogs: tens of thousands of rabies deaths

Dogs are on the list because of rabies, a virus spread through bites and scratches. WHO says dogs are responsible for up to 99% of human rabies cases. Estimates of rabies deaths range from about 44,000 a year (WHO’s 2021 Global Health Estimates) to the long-quoted figure of 59,000, with many cases never reported. More than 95% of deaths occur in Africa and Asia, and about 40% of victims are children under 15.

Once symptoms appear, rabies is virtually always fatal, but deaths can be prevented by prompt treatment after a bite. Anyone bitten or scratched by an animal that might carry rabies should seek medical help immediately. Rabies spread by dogs has been eliminated from Western Europe and the United States; in the US, most of the rare human cases now come from contact with bats.

4. Freshwater snails: about 14,000 deaths a year

Freshwater snails in tropical rivers, lakes and irrigation canals are hosts for parasitic flatworms called schistosomes. Larvae released by infected snails can enter human skin in the water, causing schistosomiasis, which damages the liver, bladder and other organs. WHO currently estimates about 14,000 deaths a year, although the disease disables far more people than it kills.

5. Kissing bugs: more than 10,000 deaths a year

Kissing bugs, or triatomine bugs, feed on blood at night in parts of Latin America. Their droppings can carry the parasite Trypanosoma cruzi, which causes Chagas disease. Many infected people feel well for years, but some later develop serious heart or digestive problems. WHO estimates more than 10,000 deaths a year.

6. Sand flies and tsetse flies

Tiny sand flies spread leishmaniasis. Its most serious form, visceral leishmaniasis or kala-azar, is fatal in more than 95% of cases if untreated, and WHO estimates 50,000–90,000 new cases a year.

Tsetse flies, found only in sub-Saharan Africa, spread sleeping sickness. Older rankings credited them with about 10,000 deaths a year, but control programs have cut new cases by 97% in 20 years. Fewer than 1,000 cases have been reported each year since 2018.

7. Crocodiles: hundreds of deaths a year

Crocodiles are the deadliest large predators. The Nile crocodile is thought to kill hundreds of people a year in sub-Saharan Africa, more than all other crocodilians combined, although many attacks go unreported. The saltwater crocodile in Southeast Asia and northern Australia and the mugger crocodile in India also cause deaths. Most attacks happen when people fetch water, wash, fish or cross rivers. American alligators cause only occasional deaths.

8. Hippos: often quoted at 500 deaths a year

Hippos are big, territorial and quick to defend their water and their young. They can overturn boats and charge people on land, especially at night when they leave the water to graze. A figure of about 500 human deaths a year is widely quoted, but no reliable global count exists. For the reasons behind their reputation, read Why are hippos so dangerous?

9. Elephants and big cats

Conflicts between people and elephants grow as farms spread into elephant habitat. In India alone, government figures record roughly 500 human deaths a year in encounters with elephants, and elephants also kill people in Sri Lanka and parts of Africa. Lions, tigers and leopards also kill people in some regions, such as rural Tanzania and the Sundarbans mangroves of India and Bangladesh, but their combined total is much smaller than that of crocodiles.

Deadliest animals at a glance

The deadliest animals in the US and Europe

In the United States and Europe, malaria and dog rabies are no longer spread locally, so the picture is very different. The animal most often named as America’s deadliest is the deer. In 2024, 210 people died in US crashes in which a vehicle first hit an animal, and in one review of such crashes, 77% of the animals were deer. Across Europe, too, collisions with deer and wild boar pose a far bigger risk to people than any wild predator.

Stinging insects such as bees, wasps and hornets, which can trigger severe allergic reactions in some people, cause dozens of deaths a year in the US, many more than snakes or sharks. Venomous animals worldwide are compared in our list of the most venomous animals.

Why sharks rank so low

Sharks are among the most feared animals but rarely kill people. The International Shark Attack File recorded 65 confirmed unprovoked shark bites worldwide in 2025, 9 of them fatal, close to its five-year average of about 8 deaths a year. That is a tiny risk compared with drowning or traffic on the way to the beach.

The danger runs the other way. People kill tens of millions of sharks every year, with estimates of around 100 million, mostly through fishing. To put the risk in context, read How often do sharks attack humans?

How to stay safe around dangerous animals

Most risks from large animals can be reduced by keeping a respectful distance: never approach hippos, crocodiles, elephants or big cats, and follow local advice and warning signs near rivers and in parks. Do not handle snakes, and leave any animal that behaves strangely alone. If you are bitten by a snake or by any animal that might carry rabies, seek emergency medical help immediately.