If You Know 21/35 of These Facts, You May Deserve a PhD


By: Robin Tyler

5 Min Quiz

Image: Getty Images via Liyao Xie

About This Quiz

The world is indeed a strange place.

Sometimes, you cannot actually believe some of the true facts that pertain to our world, its people and the fauna and flora that we find on our beautiful planet. 

For instance, did you know that earth is the only planet not named after a god? What about the fact that "hello" wasn't a greeting used until the telephone came along. And who introduced it? Thomas Edison. Although, the inventor of the telephone wanted the greeting to be "Ahoy!" Let's all just agree that "Ahoy" is infinitely cooler!

Or did you know that elephants can't jump (which let's be honest, seems pretty logical)? Sticking with the animal world, a tarantula (shudder!) can live without food for 24 months and the tongue of a blue whale is heavier than an African elephant. 

Interesting facts, right? And you will find many more in our quiz. Except you have to answer them. Do you think you can do it? Some are extremely difficult, so a score of 21 out of 35 will be excellent. 

So what you waiting for! Jump right in and show us what you are made of! You got this!

Good luck, and enjoy it!

While a dolphin gives birth, other dolphins will ________

Although this is often called an "aunty" dolphin, it can be a male or female. This is often the only dolphin a mother will let near her newborn.


Catnip also affects wild cats like lions and tigers. Is this statement true or false?

As the domestic cat is related to wild cats, it makes sense that catnip would affect the larger, wild animals as well. And you don't need bigger quantities either.


What is the fastest land animal on the planet?

An endangered species, sadly only around 7,000 cheetah are left in the wild. They can reach around 112 km/h when running.


The oldest star discovered in the universe is ________ years old.

13.8 billion! That's insane, we are sure you would agree! No wonder it has been called Methuselah.


Is your left lung smaller than your right lung?

Yes, it is. This is to make room for your heart.


We all blink, right? All the blinking we do in one day equates to having your eyes closed for how long?

Crazy, right. Blinking is needed to help lubricate our eyes. We do it around 20 times a minute and over 28,000 times a day. All that equates to 30 minutes our eyes are closed from blinking each day.


The ocean is rich with both fauna and flora. How much of the world's plant life is actually found there?

Yes, 85% of the plant life on this planet is found under water. There is still so much that we don't know about the ocean, so that percentage may still rise as we discover new areas.


What is the only bird in the world that is able to fly backward?

Hummingbirds are incredible! They flap their wings around 80 times a second and not only hover but fly backward as well.


Which continent on Earth is the only one with no active volcano?

The smallest continent by landmass and second smallest in terms of population, Australia is the only one that does not have active volcano.


What makes a strawberry unique?

Yes, the black bumps on the skin of the strawberry are its seeds. This means that it is not really a berry either!


Can you name the largest organ in the human body?

That's right, the skin is considered an organ. Seeing that it covers your whole body, it is therefore the largest organ.


Which part of their bodies do elephants use to help regulate their body temperature?

Yes, elephants move their ears to regulate their body heat. Seems reasonable, they are pretty big so would generate a wind to cool them, surely! They also increase blood supply to their ears when they are hot, allowing heat to escape.


The pupil of an octopus is rectangular. True or false?

Yes it is. They are not the only animals either. Sheep, goats and toads also have rectangular eyes.


How can you tell if an egg is hard-boiled or raw?

Hard-boiled eggs spin more than a raw egg as they are solid.


At what age do oak trees first produce acorns?

Yes that's right, depending on the species, it takes an incredible 20 to 30 years before trees produce their first acorns.


Which of these oceans is the saltiest?

The Atlantic wins the battle of salt. Although it varies across certain parts of each ocean, overall the Atlantic is saltier than the Pacific and Indian ocean


Which of these are immune to many types of diseases?

Just to make them just a little more scary, sharks are immune to many diseases. Influenza is not going to take out Jaws. They have been seen with cancerous growths, though.


Any idea as to the most active muscle in your body?

That's right and it stands to reason that the eye is the most active muscle in the body. The muscles of the eye move almost constantly to readjust its position.


Dogs sweat through their _______

When dogs get hot they pant to regulate their heat, but sweat through areas not covered by fur which include their paws and their noses.


Fredric Baur, the inventor of the Pringles can, had his ashes buried in one when he died.

Strange, but true!


What is the most song sung in the world?

Yes, the most popular sung song in the world is "Happy Birthday." It is sung millions of times around the world each day, well in English-speaking countries that is.


What color do you see if you open your eyes in a pitch black room?

Eigengrau, also called brain gray, is the color that is formed when light is absent.


Sea otters hold hands while sleeping. True or false?

How cute! But it is for a reason. It is to stop them from drifting apart while they sleep.


What's the national animal of Scotland?

Strange but true, the national animal of Scotland is the unicorn. And it has been since the 1300s.


How long does the shortest regular commercial flight take?

Yes, just 53 seconds with a tail wind. The flight takes place between the Orkney islands of Westray and Papa Westray near Scotland.


Animal rights organization PETA asked music group, the Pet Shop Boys to change their name to the Rescue Shelter Boys. True or false?

Yes, in 2009 this actually did happen. The Pet Shop Boys declined.


How long does a person on average spend waiting for a traffic light to turn from red to green in their lifetime?

What a waste of time! 6 months, incredible!


What color would Coca-Cola be without coloring?

Yes, green! Some secret recipe, that. Just what is actually in it?


What is the speed of a human sneeze?

100 mph! Please remember to cover your nose and mouth!


How long does it take a sloth to travel a mile (if it wanted to, that is)?

A month, yes. If a sloth chose to travel a mile, it would take month.


Coconuts kill how many people around the world each year?

Killer coconuts! Beware ... but it's true,


Are avocados poisonous to birds?

Yes! Avocados are very poisonous to birds. This is due to a toxin called persin which is fatal to all birds.


Which animal never stops moving, even when it sleeps?

Yes, sharks move when they sleep. Why? They need water traveling over their gills to breathe properly, and they don't have swim bladders.


Can dragonflies walk?

No they can't. Despite having six legs, they cannot walk. They are simply too weak to do so. They can hold prey, however.


"I will be there in a jiffy." How long is a jiffy exactly?

That's quick. So, if someone says they will be there in a jiffy, they won't.


Explore More Quizzes

About HowStuffWorks Play

How much do you know about dinosaurs? What is an octane rating? And how do you use a proper noun? Lucky for you, HowStuffWorks Play is here to help. Our award-winning website offers reliable, easy-to-understand explanations about how the world works. From fun quizzes that bring joy to your day, to compelling photography and fascinating lists, HowStuffWorks Play offers something for everyone. Sometimes we explain how stuff works, other times, we ask you, but we’re always exploring in the name of fun! Because learning is fun, so stick with us!