Hippos are large,
loud,
and dangerous.
They kill 500 people a year in Africa,
and their attacks are vicious.
So if you’re around one,
keep your guard up.
And don’t be fooled by its big, cute face.
'Well look at this little fella."
That hippo might be hungry.
These water-loving creatures can grow
up to 5 m long (16.5 ft),
and they weigh up to 4,500 kg (9,920 lb).
It takes a lot of energy
to carry all that mass around,
Luckily, they’re herbivores,
for the most part.
There have been reports of
hippos eating carrion,
but they’re rare.
Humans are definitely not in their diet.
But that doesn’t mean you can relax
around hippos.
They’re incredibly aggressive.
And there’s one warning sign
that you should never ignore.
If you see a hippo open its mouth
in a yawn or laugh,
you’re in trouble.
This is a sign that it's going to attack.
You think I’m going to tell you to run?
Sorry,
but hippos can charge at up to 30 km/h (18 mph).
And sometimes,
there’s no warning at all.
Hippos will often glide underneath a small boat,
flipping it and throwing its
passengers into the water.
Once you're in the water,
your chances of surviving are slim.
While they’re big animals,
a hippo wouldn’t be able to consume
you in one bite.
Instead, you’d feel intense pressure
as the hippo begins to
crush your arms or legs with its teeth.
You punch the hippo right in the nose,
and it loosens its grip on your body.
But although you manage to break free,
you’re in bad shape.
There are huge holes
in your side from its tusks.
Parts of your body are unrecognizable.
And you’re missing an arm.
That arm is still in the hippo's mouth.
Now, while you’re being rushed to the nearest hospital,
what happens to your missing limb?
Hippos have a unique digestive system.
They have three stomach chambers,
and they use a method called foregut fermentation.
Microbacteria living in hippos’ stomachs
break down food
early in the digestion process.
It's a symbiotic relationship
that allows hippos to get the most nutrients
out of tough grasses.
So, after your arm travels down the hippo's throat,
and goes into the first chamber of its stomach,
microbacteria would begin to break down your arm.
Then your arm would pass on to the true stomach.
This is where digestive enzymes
would continue to break it down.
Later, the hippo would
fling remnants of your arm,
and some grass,
over the beast's territory.
Hippos can spread their feces up to 10 m (33 ft) around them.
This plays an important role
in the rivers and lakes of Africa.
By eating and excreting grass,
hippos add silicon into Africa's water systems.
And that's good because
unicellular algae need silicon to thrive.
The algae produce oxygen,
and it's a key part of the food web.
Hippos are extremely territorial.
And they're obsessive about
protecting their young.
So while baby hippos sure are cute,
you should always steer clear of them.
Most attacks happen because
mother hippos see
humans as a threat to their offspring.
And hippos aren’t the only animal
you'll have to worry about in Africa.
The Nile crocodile is another aggressive beast,
and it attacks over 300 people every year.
But that’s a story for another What If.