The Most Dangerous Animals in the World

Mosquito species transmit a number of deadly diseases to humans.
Mosquito species transmit a number of deadly diseases to humans.

The list of world’s most dangerous animals is dominated by tiny, often-overlooked animals, with the hippopotamus and crocodile being the only notable exceptions. Indeed, some of the smallest animals are among the world’s deadliest creatures, with millions of human deaths being attributed to them each year. An excellent example of this fact is the deadliest of them all, the mosquito which makes up for what it lacks in size with deadly pathogens. Other surprising entrants of similar size include the tsetse fly and the killer bee.

10. Tsetse Fly

Tsetse flies are small parasitic flies that exist in large concentrations in sub-Saharan Africa. These flies feed on the blood of animals, including humans and in the process infect their hosts with pathogens known as trypanosomes. The trypanosomes are the reason for the deadliness of tsetse flies, as these pathogens cause the sleeping sickness, a dangerous disease that affects the human lymphatic and central nervous system. Vaccines for the disease do not exist, and the only prevention against infections is avoiding being bitten by the deadly tsetse fly.

9. Pufferfish

The puffer fish is relatively small, with only a few species exceeding 30 inches in length. However, the puffer fish has the most potent venom of any fish in the world, believed to have 100 times the potency of cyanide. The poison is the fish’s primary defense mechanism and is lethal in humans. Interestingly, the fish is served as a delicacy in some regions of Asia. In Japan, only licensed chefs are allowed to prepare the puffer fish, but that notwithstanding reports of fatal poisoning from puffer fish consumption are reported each year in the country.

8. Saw-Scaled Viper

The saw-scaled viper is a venomous snake ranging between 15 and 30 inches in length. Despite its relatively small size, the saw-scaled viper is one of the most dangerous animals on earth. The reason behind the deadliness of the viper is its excellent camouflage and preference of residing in regions with dense human populations. Due to its small size, the snake avoids humans, and only attacks when provoked. When biting, the saw-scaled viper injects about 12 milligrams of venom into the victim’s bloodstream, with the lethal dose in adult humans being only 5 milligrams.

7. Crocodile

Crocodiles are the deadliest of reptiles and are among the world’s most dangerous animals. Adult saltwater crocodiles and Nile crocodiles attain immense sizes (over nine feet in length). Crocodiles of these two species are also the few animals on earth that actively prey on humans. Hundreds of fatal attacks have been attributed to one individual, a gigantic Nile crocodile known as Gustave which has been preying on humans in Burundi’s Rusizi River. Crocodile attacks on humans are not restricted to the wild, as numerous attacks have been reported in game parks.

6. Killer Bees

Bees are known to be dangerous insects, and swarms have killed many people throughout history. The bee that is regarded as the deadliest in the world is the Africanized bee, which is also known as the “killer bee.” The bee’s name is a testament to its deadly infamy, with an estimated 1,000 human fatalities being attributed to the killer bee. Among the characteristic traits of the Africanized bees is their tendency to guard their hive with a level of aggression not seen in other bee species. Swarms of killer bees have been reported to chase victims for about 0.75 miles and inflict ten times more stings than those recorded in European bees.

5. Golden Poison Dart Frog

Another deadly tiny animal is the golden poison dart frog. It is a small frog species with adults reaching 2 inches in length. The frog gets its name from the poisons it secretes and coats its skin. The most common of the poisons are the alkaloid toxin. The poison is so toxic that one milligram is enough to kill about 20 people or 10,000 mice. However, the frog only uses the poison defensively as they are not venomous. The golden poison dart frog is found in the rainforests of Colombia where indigenous people traditionally used poisons carefully extracted from the frog to coat arrow-heads.

4. Tapeworm

The tapeworm is a parasite that thrives in animals. The worm can grow up to about 10 feet in length, with some even reaching 26 feet in length. The tapeworm’s natural habitat is inside the digestive tract of animals and humans and is spread to humans through the consumption of undercooked or uncooked meat. The parasitic worm has been linked to anemia and emaciation in humans. However, the deadliest disease spread by the tapeworm is cysticercosis which is believed to kill an estimated 400 people each year.

3. Hippopotamus

The hippopotamus is the world’s third-largest terrestrial mammal, only surpassed in size by the elephant and the rhinoceros. This herbivorous animal is regarded as the world’s deadliest mammal, killing an estimated 500 people each year. The aggression of the hippo is unrivalled among large animals and they will attack humans even when they are not provoked. While the majority of hippo attacks occur in water bodies, there are also numerous accounts of a hippo attacks on land. Despite being over 2,500 pounds in weight, the hippo can reach speeds of 19 miles per hour, making the colossal mammal much faster than humans.

2. Box Jellyfish

The marine animal with the most potent venom, the box jellyfish is the most dangerous marine creature on earth. The box jellyfish is so named due to its frame that takes the shape of a cube, from which about 15 tentacles extend. These tentacles which can be 10 feet in length are lined with stinging cells known as nematocysts in their thousands, each containing a neurotoxin. Box jellyfish do not actively attack humans, but due to their virtually transparent body, swimmers are at risk of getting entangled with their deadly tentacles. While there exists an antidote for the neurotoxin, survival from the attack is dependent on the speed at which the antidote is administered to a victim as the neurotoxins are fast-acting.

1. Mosquito

The mosquito tops the list of the world’s most dangerous animals, surpassing all other animals in human deaths. Governments and international organizations around the world spend billions of dollars each year to combat the tiny mosquito. Some mosquito species including the Culex, Aedes, and Anopheles species are vectors of pathogens which cause a variety of deadly diseases such as the dengue fever, Zika, Chikungunya, yellow fever, and elephantiasis. However, the disease that the insect is most infamous for is malaria, an infectious disease that has killed more people in history than any other. One statistic has it that a human dies of the disease after every 30 seconds. The World Health Organization puts the number of people infected by the disease around the world at about 0.7 billion.


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