Tuesday marks a special day for one of the most popular pets: Cats. The International Cat Day, created by International Fund for Animal Welfare, was first celebrated in 2002.

The day was created to encourage people to adopt more cats, as only 37 percent of the 3.4 million cats in the U.S. that enter shelters every year find homes.

With people doting over their furry friends, no wonder International Cat Day has gained a lot of popularity in recent times.

While cat owners across the world spend the day treating their pets, many Twitter users Tuesday shared pictures and messages about their cats on the social media site.

READ: Pet Cat History: DNA Shows Wildcats First Domesticated in Egypt, Western Asia

Here are some interesting facts about cats:

  • Cats spend a lot of time grooming themselves. This helps them in keeping themselves cool and allows adequate blood flow in their body. This also helps them in toning down the smell of their body, in order to avoid predators. Grooming is also regarded as a sign of affection between two cats.
  • The world’s oldest cat is a Siamese named Scooter. He is 30 years old and lives in Mansfield, Texas.
  • Cats have an excellent sense of balance, and they're able to tell “up” from down when they are falling and adjust their bodies accordingly. Additionally, cats can spread their legs out to glide through the air, reports said.
  • In 1963, French scientists launched the first cat into space. Its name was Félicette.
  • Cats are not communal creatures; while the male prefers to hunt alone, female cats work together while rearing kittens. They are very specific while choosing their company, and tensions do get high when forced by humans to live with other cats.
  • It is mostly believed that cats are happy when they purr. However, this is not true. Cats also purr when they are in pain, hungry or hurt, reports said.
  • Kidney failures are very common in cats, and many a time leads to early death. It has been found that leaves, pollens, and petals of certain flowers contain toxins that cause kidney failure in cats.
  • Just as many people are allergic to cats, some cats are also allergic to human beings. It is believed that one out of 200 cats suffers from asthma. Cigarette smoke, human dandruff, and dust can worsen their condition, reports said.
  • There are many beliefs linked to cats in different parts of the world. While black cats are considered bad omen in the U.S., they are considered auspicious in the United Kingdom and Japan. Germans believe that if a black cat crosses the path from left to right, it is ominous. However, the reverse is not regarded as the same, reports said.
  • The first major cat show in the world was held in 1871. Hundreds of cats and more than 200,000 guests attended the function, reports said.
  • Cats spend 50 percent of their lives sleeping. They sleep for 13 to 16 hours a day.

READ: Do Cats Like Their Owners?

  • Cats are not able to taste sweet things.
  • The heartbeat of cats is two to three times faster than that of humans, reports said.
  • The whiskers of cats act as a sensor for them and help them understand if they can fit in a space or walk through it.