The Internet is filled with pseudo-facts, and it is hard to know which ones you can actually believe. For example, a woman buying invisible artwork for $10,000 or a shrimp throwing a better punch than you might sound absolutely crazy and totally fake, but these are actually true! We live in a fascinating world, and oddities exist everywhere in science, nature, human history, and everyday life. Here, we have compiled a list of 10 such compelling facts that are hard to believe. Whether you are looking for pure amusement or interesting icebreakers, you are surely going to enjoy these!

1 Spain is one of four countries in the world that have no words in its national anthem.

Spain, San Marino, Kosovo, and Bosnia and Herzegovina are the only four countries in the world to not have lyrics in their national anthem. The “Marcha Real,” Spain’s national anthem, was composed in 1761 by Spanish oboist, director, and composer, Manuel Espinosa de los Monteros. The tune was originally composed for the Spanish Infantry as a military step.

In 1770, it was declared Spain’s official march by Spain’s King Charles III. As a result, it was formally played during solemn acts in public. Later, during the reign of Queen Isabel II, “Marcha Real” became the official national anthem of Spain.

After the Glorious Revolution that took place in 1868, there were plans for replacing the “Marcha Real” as the national anthem. General Prim even held a nationwide contest for coming up with a new national anthem, but, it did not work to his favor. Again, during the Second Spanish Republic that occurred between 1931 and 1939, the “Himno de Riego” briefly replaced “Marcha Real” as the official national anthem.

Finally, when the Spanish Civil War ended, Spanish politician and general, Francisco Franco returned “Marcha Real” to its former glory of being the country’s official anthem. However, the title was changed to “La Marcha Granadera.”

The fact that it is one of the oldest national anthems in the world is not the only noteworthy aspect. The most striking thing about Spain’s national anthem is that it has no official lyrics. During the dictatorship of Francisco Franco, the national anthem did have lyrics. However, after Franco’s death, when Spain became a democratic country, the lyrics were officially dropped.

Though several attempts have been made to add words to the anthem, the Spanish government has rejected all of them. The present version of the anthem is a 16-bar phrase with no words, and the phrase has two sections that follow an AABB pattern. There are also three different official arrangements: one for organ, one for a military band, and one for an orchestra. (1, 2)

2 A woman once bought an invisible piece of art for $10,000.

Back in 2011, artist duo Delia and Brainard Carey along with American actor James Franco, introduced a project called “MONA” or “Museum of Non-Visible Art.” They even launched a fundraising campaign on Kickstarter to gain financial support for this mythical museum. As ludicrous as it sounds, a woman actually bought one of their invisible art pieces for $10,000!

Aimee Davison, a new media enthusiast, bought the piece titled “Fresh Air” to show her support for the project. The unique art piece, which does not exist physically, was described as having “an endless tank of oxygen.” Because of her generous contribution to the project, Davidson will receive only a display card that will explain the idea and inspiration behind the art piece.

When asked, Aimee Davison said that the reason she purchased the art was that she felt inspired by the idea that MONA aspires to “exchange ideas and dreams as currency in the New Economy.” She also stated that “Fresh Air” supports her thesis of what she calls “you-commerce,” which is the act of monetizing and marketing one’s skills, persona, and products via social media. (1, 2)

3 Two sisters in Virginia sold an Illinois-shaped cornflake for $1,350 on eBay.

Back in 2008, sister duo Melissa and Emily McIntire from Virginia sold a cornflake for $1,350. If you are wondering what was so special about the single cornflake, the answer is that it was shaped like the U.S. state of Illinois.

The week-long auction was held on eBay until a trivia website owner by the name of Monty Kerr bought the item. The Texas man was building a collection of American and pop-culture items and thought that the cornflake would be a great addition to that.

The sisters had originally listed the cornflake on the popular auction site, but eBay quickly removed it saying the listing violated their food policy.

So, they auctioned a redeemable coupon instead. Kerr, the winner of the auction, said he would visit Virginia or send someone there to pick up the item in person to avoid damage. The sisters, on the other hand, had stated that they would take a family vacation with the money earned. (1, 2)

4 The mantis shrimp throws the fastest punch in the world. It punches with the speed and force of a rifle bullet.

Stomatopods, popularly known as the “mantis shrimp,” are marine crustaceans from the Stomatopoda order. Being the rather aggressive relatives of lobsters and crabs, mantis shrimps prey upon other marine animals. Their killer moves include devastating jabs that can even smash through glass walls that are a quarter-inch thick!

The creature’s secret weapon is its hinged arms that stay folded and hidden away under the head. It can unfurl these arms at incredibly high speeds to cripple its enemy with powerful blows. Some species of mantis shrimp have spears which they use to stab soft-bodied prey such as fish. However, the “smasher” species have heavy clubs attached to their arms. This species of mantis shrimps are known to punch at the force of a rifle bullet.

Scientists have discovered that the shrimp have spring-loaded arms that help them swing their clubbed “fists” at a speed of 23 meters/second. The saddle-shaped structure right above the clubs plays a major role in the shrimp’s ability to pack a punch. It is a two-layer structure. The top one is made up of a ceramic-like substance that feels like bone, and the second layer is composed of biopolymers, which is a material similar to plastic.

When the shrimp bends the saddle-like structure, it compresses the top layer and stretches the bottom layer. The bony top layer can pack a lot of energy when compressed, but it is also brittle when stretched or bent. The bottom layer, on the other hand, is stretchy and strong thanks to the biopolymers. The combination helps to maintain the force of the punch without causing damage to the shrimp. (1, 2)

5 Frogs use their eyeballs to push food down their throat.

Have you ever watched a frog eat? If so, you must have noticed how it closes its eyes or blinks while swallowing. This is not because the frog is enjoying its meal, but because the creature uses its large eyeballs to push food down the throat! Back in 1906, biologist Mary Dickerson first proposed the idea that toads and frogs press their eyes down into the roof of their mouth as it helps them to swallow. In doing that, the eyes work as a trash compactor.

However, the theory would not be tested until 2004 when a group of biologists from Massachusetts University started studying a leopard frog’s eye movement while eating. They took x-ray videos of the animal while it ate. The results showed that the frog did push its eyes down to the roof of its mouth to push the prey down towards the pharynx. The electrical activity also showed that the eye retractor muscles were activated on purpose.

Finally, in an experiment, the scientists cut the nerves present in the retractor muscles. The results showed that the frogs were still able to swallow even though they could not close their eyes. However, the animal had to work twice as hard to push down the same amount of food. The study hence proved that frogs do use their eyes to swallow. (1, 2)