The Fact Ledger

A group of pugs is called a grumble.

This name comes from the low-pitched snorts and grunts pugs make. When many pugs gather, their combined noises sound like people grumbling.

The inside of your lungs has enough surface area to cover a tennis court.

Your lungs are filled with millions of tiny air sacs called alveoli. If you unfolded all these sacs and laid them flat, they would cover about 70 to 100 square meters.

You cannot sink in the Dead Sea because the water is too salty.

The water contains about 34% salt, making it much heavier than a human body. This high density creates a strong upward force that keeps you floating on the surface.

Oxygen turns into a pale blue liquid or solid when it is frozen.

Oxygen gas has no color. When it gets cold enough to turn into a liquid, its molecules absorb red light and reflect blue light to your eyes.

A tiger has striped skin, not just striped fur.

If you shaved a tiger, the same pattern of stripes would still be visible on its skin. These markings are unique to every tiger, much like human fingerprints.

Your body replaces your entire skeleton about every 10 years.

Special cells constantly break down old bone and build new bone in its place. This process keeps your bones strong and repairs small cracks from daily use.

Tofu contains more protein than ground beef when comparing equal amounts of calories.

Tofu provides about 11 grams of protein for every 100 calories. Ground beef with 20% fat provides about 8 grams of protein for the same number of calories.

William Shakespeare was a professional actor who performed in his own plays and owned part of his theater company.

Shakespeare did not just write plays. He spent most of his career on stage as a member of a group called the Lord Chamberlain's Men. He often played smaller roles so he could watch...

William Shakespeare wrote many of his famous poems because the plague forced London theaters to close.

The bubonic plague made public gatherings illegal in the 1590s. Shakespeare could not perform plays for an audience, so he wrote poetry to earn money from wealthy donors.

The first written record of William Shakespeare as a playwright was a public insult calling him an 'upstart crow'.

In 1592, a rival writer named Robert Greene attacked Shakespeare for being an uneducated actor who dared to write plays. This insult shows that Shakespeare was already successful e...

William Shakespeare wrote at least two plays that are completely lost.

Records from his time list titles like 'Cardenio' and 'Love's Labour's Won'. No copies of these scripts exist today because they were never printed or the original papers were dest...

William Shakespeare's tombstone features a curse to stop people from moving his bones.

During the 1600s, workers often dug up old graves to make room for new ones. Shakespeare had a warning carved on his grave to ensure his body stayed in the ground forever.

William Shakespeare never spelled his own name as 'William Shakespeare' in any of his surviving signatures.

During his life, spelling rules did not exist. People often spelled words and names based on how they sounded at the moment.

William Shakespeare invented or first recorded more than 1,700 English words.

He created new words by changing nouns into verbs and joining separate words together. He also added prefixes and suffixes to existing words to give them new meanings.

National Napping Day was created in 1999 to help people recover from losing an hour of sleep when clocks move forward for Daylight Saving Time.

This day happens every year on the Monday after the spring time change. Losing one hour of sleep makes people more tired and less alert. A short nap helps the body catch up and sta...

The United Nations officially recognized International Women's Day in 1975.

Before this, the day was mostly celebrated by labor groups and socialist countries. The UN's decision turned it into a global event for all 193 member nations to focus on women's r...

International Women's Day is on March 8 because of a calendar difference during a 1917 Russian protest.

Russian women started a massive strike for food and rights on February 23 by their local calendar. Most other countries used a different calendar where that same day was March 8. T...

Goldfish can remember information for at least five months and can learn to recognize colors, sounds, and faces.

The idea that goldfish have a three-second memory is a myth. Their brains allow them to link specific signals, like a light or a sound, with a food reward.

Ancient Romans used pigeon droppings and vinegar to bleach their hair blonde.

Light hair was a sign of high status and youth in Roman society. Since most Romans had dark hair, they used the acid in bird waste to strip away their natural hair color.

A honeybee colony visits 2 million flowers and flies 55,000 miles to make one pound of honey.

Bees collect sugary nectar from flowers and carry it back to their hive. They fan the nectar with their wings to remove water until it becomes thick honey.

Crows can remember a human face for over 10 years and tell their friends which people are dangerous.

Crows use facial recognition to identify people who have threatened them. They use loud alarm calls to warn other crows about these specific individuals. This allows the whole grou...

The North Pole has no land and is just a sheet of ice floating on the ocean.

Unlike the South Pole which sits on a continent, the North Pole is located in the middle of the Arctic Ocean. The ice here is only about 2 to 3 meters thick and floats on water tha...

Victorian inventors created special spoons and teacups with built-in guards to keep moustache wax from melting into hot drinks.

Men in the 1800s used stiff wax to style their large moustaches. Steam from hot tea or soup would melt this wax, making the hair droop and ruining the flavor of the liquid.

A day on Mercury lasts twice as long as its year.

Mercury orbits the Sun very quickly but spins on its axis very slowly. It takes 88 Earth days to circle the Sun, while one full day from sunrise to sunrise takes 176 Earth days.

Squirrels cannot vomit or burp because their stomachs have a one-way valve that is too strong to open backward.

A thick muscle between the stomach and the throat acts like a security gate that only opens inward. This means once a squirrel swallows something, it cannot come back up.

The smell of freshly cut grass is a chemical distress signal used to warn other plants and call for help.

When grass is damaged, it releases chemicals called Green Leaf Volatiles. These chemicals tell nearby plants to prepare their defenses and attract insects that protect the grass.

Tug of War was an official Olympic sport for 20 years.

It appeared in five Summer Games between 1900 and 1920. Teams of eight people competed to pull their opponents a distance of six feet.

Rats laugh when they are tickled or play with each other.

They make high-pitched chirping sounds that humans cannot hear without special equipment. These sounds show the rats are happy and enjoying themselves.

Saffron is the most expensive spice in the world because it takes 75,000 flowers to make just one pound of it.

Each flower only grows three tiny red threads called stigmas. Workers must pick these threads by hand because machines would crush the delicate plants.

A Greyhound named Star Title set the world record for the fastest dog by running 41.83 mph (67.32 km/h).

Greyhounds use a special running style where all four paws leave the ground twice in every stride. Their bodies have extra-large hearts and flexible spines that work like springs t...

A rare copy of the first Teenage Mutant Ninja Turtles comic book sold for $250,000.

The creators only printed 3,275 copies of the first issue in 1984. Most comics at that time had hundreds of thousands of copies made.

April O'Neil was originally a computer programmer and lab assistant rather than a news reporter.

The 1987 cartoon changed her job so she could find out about crimes quickly. This gave the Ninja Turtles an easy way to get information for their missions.

The Teenage Mutant Ninja Turtles villain Shredder was inspired by a metal cheese grater.

Co-creator Kevin Eastman was washing dishes when he put his arm inside a rectangular grater. He realized the sharp metal edges would make a dangerous weapon for a character.

The Teenage Mutant Ninja Turtles are named after famous Italian artists because their creators could not think of enough Japanese names.

Kevin Eastman and Peter Laird wanted names that sounded unique. They used an art history book to find names that fit their new characters.

Scooby-Doo's full legal name is Scoobert Doo.

Characters use this formal name when they want to be serious or during family events. It appears on official documents in the show and in the live-action movies.

The Mystery Machine from Scooby-Doo is a mix of different real-life vans from the 1960s.

Artists combined parts from the Ford Econoline and the Chevrolet Corvair to create the famous van. Its bright colors and flower stickers were based on popular art styles from the l...

Shaggy from Scooby-Doo became a vegetarian because his voice actor refused to promote meat.

Casey Kasem was a vegan who wanted Shaggy to share his beliefs about animal rights. He only agreed to keep voicing the character if the show's producers changed Shaggy's diet.

Scooby-Doo was created to replace violent superhero cartoons after parents complained about TV fighting.

In the late 1960s, groups like Action for Children's Television protested aggressive shows. CBS asked for a new series that used comedy and mystery instead of physical combat to so...

Scooby-Doo was originally a sheepdog named Too Much who played the drums in a rock band.

Creators Joe Ruby and Ken Spears first pitched a show about five teenagers and their dog in a band. They changed the dog's breed and name to make him stand out from other cartoon d...

The inventor of the Pringles can was buried inside one of his own cans.

Fredric Baur designed the tall tube in 1966. He was so proud of the invention that he asked his family to use it as his burial urn. When he died in 2008, his children placed part o...

The Pacific Ocean shrinks by about 2 to 3 centimeters every year.

Tectonic plates under the ocean are sliding beneath other plates and sinking into the Earth's interior. This process removes more of the ocean floor than is being created.

A group of porcupines is called a prickle.

Porcupines usually live alone. They only gather in groups to stay warm during winter or to find a mate. The name comes from the thousands of sharp quills covering their bodies.

Moonquakes can last for up to 10 minutes because the Moon vibrates like a ringing bell.

Earthquakes usually stop within seconds because water and soft minerals in the ground absorb the energy. The Moon is dry and rigid, so vibrations bounce around inside it for a long...

Sunlight takes about eight minutes and 20 seconds to reach Earth.

The Sun is 93 million miles away. Even though light is the fastest thing in the universe, it still takes time to travel that distance. When you see the Sun, you are seeing what it...

Germany has about 25,000 castles, almost double the number of McDonald's restaurants in the United States.

Germany has roughly 25,000 castles—nearly double the number of McDonald's in the U.S. (approx. 13,500). This massive density exists because, during the Middle Ages, Germany wasn't...

Pigs cannot look straight up at the sky because of the way their necks are built.

The bones and thick muscles in a pig's neck do not let them tilt their heads very far back. To see something directly above them, they have to lie down or walk backward to change t...

The Hundred Years' War lasted 116 years and was not one single war.

It was a long series of separate battles and peace breaks between England and France. The fighting happened on and off from 1337 to 1453.

The first SMS ever sent said "Merry Christmas" and was sent on December 3, 1992.

A 22-year-old engineer named Neil Papworth sent the message from a computer to a mobile phone. At that time, mobile phones did not have keyboards, so they could receive texts but c...

The bulldog Spike from Tom and Jerry was originally named Killer.

He first appeared in the 1942 cartoon Dog Trouble. Animators changed his name to Spike a few years later to make him sound less aggressive.

A single seven-minute Tom and Jerry cartoon required up to 14,000 individual hand-drawn pictures.

Artists drew every movement by hand on clear plastic sheets. At a speed of 24 frames per second, a short film needed thousands of unique drawings to make the characters look like t...