Why are Hippos so Aggressive and Dangerous to Humans?

Hippos are the world’s deadliest mammal, second only to humans, killing over 500 people in Africa each year. Despite being herbivores, they are highly aggressive, territorial and fiercely protective of their young.

At night, they leave their watery habitats to search for food and often enter areas where humans live.

Why are Hippos So Aggressive and Dangerous? They attack humans as a defensive measure, usually when they feel their territory or young are threatened.

Though they look slow and gentle, they can run faster than Usain Bolt and have a powerful bite force of 2,000 pounds per square inch.

Why are Hippos Dangerous?

Those statistics are somewhat surprising given that herbivorous hippos spend most of their time snoozing in the water.

At night, however, the hippopotamus leaves the safety of the water in search of the hundred pounds of greens it needs to eat daily.

These expeditions take hippos up to 10km away from their watery homes and into areas that humans also frequent.

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Why are Hippos Dangerous?

Despite being the third-largest land animal, male hippos are surprisingly skittish and will react aggressively to anything entering their territory.

A hippo on land is even more dangerous than a hippo in water, and it won’t hesitate to charge if something comes between him and his safety zone.

Getting between a hippo and deeper water can set his nerves on edge, leaving you with over 3,000 pounds of cantankerous behemoth to deal with.

Although hippos won’t go out of their way to attack other animals or even humans, if you enter their territory, they won’t think twice about defending it with everything they’ve got. That includes bulk, speed, and a set of large, sharp teeth.

Not only are adult hippos territorial, but they also guard their families ferociously. This makes them the deadliest large land animal in the world.

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At first sight of danger, they will often perform a threat sign.

To the uninitiated, this looks just like a yawn, but their motive is to show off those incredible teeth. Once you’ve had a glimpse of those giant canines, it’s time to get out of the way because that yawning hippo is anything but tired.  

Dominant male hippos use their unique hippo yawns to prove their size and strength. A hippo opens its mouth to show off its large teeth in the hopes of intimidating its potential sparring partner.

A violent fight will be needed to settle the dispute if that doesn’t work During such conflicts, a full-grown adult can easily kill baby hippos that get in the way.

Unfortunately, although the mothers will actively defend their young, this isn’t always enough to save them and a young hippo caught between two adults is unlikely to survive.

How Dangerous are Hippo Attacks?

When hippos attack humans, the outcome is almost always fatal. For example, just a few days before writing this article, a hippo attacked and killed a woman in the South African province of Kwa-Zulu Natal.

Such attacks are not uncommon in the region and are largely due to humans and hippos fighting over a vital resource – water.

On this particular occasion, the victim was harvesting a type of mat grass rather than collecting water.

However, during her search, she inadvertently entered the hippo’s territory, which had widened due to the heavy rainfall earlier in the year.

How Dangerous are Hippo Attacks?

Animals that weigh as much as 9,000 lbs, run at 30 kph, and have 50-inch-long canines will always be dangerous. When those physical attributes are combined with a naturally aggressive instinct and adult hippos’ tempers, the results are almost always fatal.

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Hippos don’t attack humans or eat people because they’re hungry – they do it to protect their resources and the other pod members or bloat.

So it doesn’t matter if you’re one of the world’s most dangerous animals. If you enter a hippo’s territory, you will likely come off second best.

This video shows what happens when lions and hippos come face to face and proves exactly who’s in charge of the Okavango Delta’s famous waterways.

What Makes Hippos Dangerous?

Hippos look misleadingly calm and gentle. Their grunts, wheezes, and honks sound comical, almost as though they’re laughing, while their oversized bodies turn bubble-gum pink in the sun.

Seeing a hippo out of the water, you could easily be lulled into a false sense of security.

But, with their short legs and lumbering bodies, they look too slow to be dangerous animals.

What Makes Hippos Dangerous?

This couldn’t be farther from the truth. Not only do hippos have a highly aggressive nature, but they’re also surprisingly fast.

Despite being the third-largest land mammal in the world, the hippo can run faster than Usain Bolt, which means they can easily outrun you.

In the water, they’re just as dangerous. Despite being known as the “river horse” a hippo doesn’t swim, but it can still propel itself through the water at an alarming rate.


Douglas McCauley, an assistant professor in the department of ecology, evolution, and marine biology at the University of California in Santa Barbara, explains that the hippo “almost always maintains some contact with the bottom and walks or bounces off the bottom using these bottom contact points as a source of propulsion.”

Not only are hippos secret speed demons, but they’re also highly territorial and readily defend their young and home. Hippos have another not-so-secret weapon in the form of their incredible jaws.

Hippos can open their mouths 150°

Hippos can open their mouths 150° and, once at full stretch, that mouth measures up to four feet wide, making it plenty big enough to wrap around your average human.

In addition to being big, hippos’ jaws are extremely powerful, with a bite force of around “2,000 pounds per square inch.”

That’s more powerful than a lion or a hyena. Even a grizzly bear doesn’t come close with a bite force of just 975 per square inch.

Why are Hippos so Aggressive to Humans?

Hippos will attack almost anything in their territory, or that threatens their young. They’ve been known to spar with crocodiles, take on lions, and even stand their ground against an angry elephant.

They lose few of these battles, so the odds are stacked in their favor when they come up against a mere human.

Hippos trample people, gore them to death, drag them into the water, and capsize boats.

The hippo’s natural aggression is just one of the reasons it behaves so aggressively towards humans. The other is water.

Why are Hippos so Aggressive to Humans?

As biologist Rebecca Lewison, head of the World Conservation Union’s hippo research group, explains, “Fresh water is probably the most valuable and limited resource in Africa.”

It’s also one that both hippos and humans need to survive. But, unfortunately, this frequently brings humans and hippos together – comfortable proximity for neither party.

Not only do people head into hippo territory for water, but they also go there for food and other resources. Fishermen risk their lives trying to wrest fish from waterways inhabited by hippos.

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Women are forced into the hippo’s territory in search of Incema, African grass mat, and thatching grass for the roofs of their traditional homes.

Circumstances bring humans and hippos into conflict, and our lack of awareness is often what sparks these violent encounters.

People can easily wander into a hippo’s territory without even realizing it, especially at night when a hippo could be kilometers away from the nearest body of water.

Hippos can hold their breaths and stay underwater for up to five minutes at a time. It is, therefore, relatively easy to drift into their territory without even realizing that they’re there.

Do Hippos Attack Humans?

Hippos won’t hesitate to attack a human that it perceives as a threat.

That includes any humans within its territory, people who’ve strayed too close to a young hippo calf, and anyone getting between them and deep water.

Do Hippos Attack Humans?

If you’re in shallow water while the hippo is wallowing in the depths, they’re relatively calm and friendly, as long as you don’t encroach on their territory.

However, if you’re standing between a hippo and the water, be prepared for a violent assault.

Do Hippos Kill Humans?

Hippos kill around 500 people every year. Unfortunately, few people experiencing a hippo charge live to tell the tale. Paul Temple is one of the lucky ones.

In 1996, Paul was working as a canoe safari guide in Zimbabwe when one of his trainee guide’s canoes was knocked off course.

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While he wasn’t far from the rest of the group, the trainee had strayed into deeper water close to where a bloat of hippos was wallowing.

Do Hippos Kill Humans?

A young male hippo took offense at his proximity and launched a violent attack that catapulted the young guide into the river.

Paul knew he had to act quickly and paddled over to his colleague, leaning over the side of his canoe in an attempt to drag him out of the water. Unfortunately, at that moment, the hippo attacked again, and the next thing Paul knew, he was up to his waist in hippo.

Paul was attacked twice more before another guide managed to rescue him. Although he survived the ordeal, he was, Paul said, “kind of like a kebab. I was a mess.”

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Paul sustained 38 major bite wounds, one of which punctured a lung. In addition, his left arm was crushed to a pulp, and bites were taken out of his foot, head, spinal column, and face.

Paul is one of the few to survive a hippo attack, with most proving fatal.

How Many Humans do Hippos Kill Every Year?

Although it’s impossible to say how many people fall victim to hippos each year, conservative estimates place it at around 500 a year in Africa.

Of course, that’s more than one hippo attack every day, and that’s only a conservative estimate. According to one source, there could be as many as 3,000 hippo attacks in a single year.

How Many Humans do Hippos Kill Every Year?

Compare that to the dreaded great white shark, and the figures seem even more shocking. Each year, there are around 70 unprovoked shark attacks, of which only a handful prove fatal.

When it comes to hippo attacks, however, more people die. One study found that the “probability of being killed by a hippopotamus attack (case fatality rate) is thought to be in the range of 29 to 87%.”

For shark attacks, it’s just over 22% and, for crocodiles, around 25%, highlighting the severity and violence of a hippo attack.

Are Hippos the Most Aggressive Animal?

Hippos are extremely dangerous, but that doesn’t necessarily mean they’re aggressive. Philip Muruthi, a conservationist with the African Wildlife Foundation, points out that, as a strict vegetarian, a hippo “has no reason to become a human habitat attacker.”

Killing humans don’t give them any nutrition or other benefits. In fact, killing one is a waste of energy that could be used for more important things, like foraging.

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Are Hippos the Most Aggressive Animal?

According to Muruthi, “Hippos will avoid humans when given a choice. They won’t try to come to human-dominated areas.” Our perspective of them as aggressive animals is, therefore, somewhat misguided.

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Hippos will tolerate humans if we respect their terms. Therefore, the better we understand the needs and habits of the hippo, the better chances we have of living peacefully alongside it.

Can a Hippo Be Friendly?

I’ve had a few close encounters with hippos that, while frightening, proved harmless to the point that the hippo could even be considered friendly.

A few years ago, I was on an impromptu kayaking trip in the Double Drift Game Reserve in the Eastern Cape of South Africa.

Heavy rains had swelled the river to the point that exceeded our abilities in the kayaks and soon found us floundering around alongside them rather than inside.

Can a Hippo Be Friendly?

After bumping over a few rapids, I finally found myself in a patch of still water. It was shallow enough for me to stand, so, griping onto my kayak with one hand, I stood waist-deep in the water, waiting for the rest of the group to arrive.

Suddenly, behind me, I heard the unmistakable grunt of a hippo. I turned, and just 50 feet away, I saw a large, grey snout emerge from the water.

The hippo surveyed me suspiciously before disappearing again under the surface.

Trying to contain my panic, I made my way to the bank as quickly and quietly as possible, dragging my kayak behind me.

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Once on dry land, I looked out over the water only to find a mirror-like surface reflecting back. The hippo had gone.

I breathed a sigh of relief and quickly helped other group members out of the water as they arrived.

Although I felt like I’d had a brush with death, I actually believe I was in no danger that day.

The hippo was in much deeper water than I and so had no reason to fear my presence. I wasn’t preventing him from accessing his safety zone, nor was I entering his territory or posing a threat to his bloat, wherever they might have been.

In this sense, I believe I was lucky enough to meet a friendly hippo or, at least, find myself in a situation where I managed not to provoke the hippo’s natural territorial aggression.


Hippos are one of the deadliest animals on earth, killing over 500 people a year in Africa. Male hippos are highly territorial, and females use their natural aggression to actively defend their young.

Hippos’ aggressive behavior towards humans is defensive rather than destructive, and hippos won’t go out of their way to attack humans.

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In fact, many hippo attacks could be avoided if people were more educated about the needs and behavior of hippos.

Unfortunately, humans and hippos need water to survive, bringing them close to one another and increasing the chances of a violent conflict.

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