Many people believe that when a sleeping dog or cat wags its tail or swats its paws, it is dreaming. While it's difficult to say for certain, researchers believe that most animals, including mammals, birds, reptiles, and fish, go through sleep stages, including REM and non-REM, and thus dream.

They may be little, but they kill millions of people each year, according to the World Health Organization. This is due to the fact that mosquitos contain and transmit a variety of viruses and illnesses, ranging from malaria to dengue fever to yellow fever. Malaria claimed the lives of 438,000 people in 2015.

Go ahead and stare at that face for as long as you like. While there are lots of charming creatures out there, none appear as perpetually cheerful as the quokka. These marsupials, found on tiny islands off the coast of Western Australia, have a lovely bone structure that makes them appear like they're grinning from ear to ear. According to National Geographic, some individuals have nicknamed them the "happiest mammal in the world."

The only vertebrates that can replace their skin, limbs, tail, jaws, and spines at any age are Axolotls. Humans, on the other hand, can recover lost limb buds as embryos and fingers as young toddlers.

Ostriches, like other modern birds, lack teeth. They eat everything from roots, plants, and seeds to lizards and insects because they are omnivores. Ostriches must swallow grit and rocks to help break down their varied diet. This unusual digestion is aided further by a number of other adaptations, including three stomachs and intestines that stretch for approximately 46 feet. 

Gorillas enjoy eating and do so virtually continuously throughout the day. Because plants constitute the majority of their diet, they require a great amount of food to sustain their sizeable muscular body. They can consume up to forty pounds (eighteen kg) of food in a single day. They have strong jaws and can chew even the toughest stems, but they also eat leaves, fruits, seeds, roots, ants, and termites. Their cousins, the chimps, eat termites and are known to utilize tools to do so. Gorillas take a brusquer method, smashing termite mounds to get to the termites inside.

The dung beetle is the most powerful bug on the planet. They can propel balls of fresh animal faeces (thus their name) weighing more than 200 times their body weight. Researchers observed one dung beetle pushing a ball 1,141 times his own weight, the equivalent of a 150-pound person moving an incredible 80 tonnes.

Snow leopards have less developed vocal chords than other large cats, so they can't roar and instead create a purr-like sound termed a chuff. Scientists investigated why certain cats have a higher-pitched meow than others in a 2010 study published in the Biological Journal of the Linnean Society. They discovered that a kitty's call is determined by environment rather than size.

The prevalent word for apes, "bonobo," may appear to be a translation of a significant term, but it was really the consequence of a mistake. The creatures were initially discovered in the 1920s in the town of Bolobo, Zaire, but the name of the town was misspelt "Bonobo" on the shipping container in which the animal was housed, prompting others to call the species by that name, which stuck.

When it comes to sleeping habits, snails are all over the place. We'll call them manic. They may slumber for many hours before staying up for 30 hours or more. On the other hand, they have bizarre hibernation periods. They can sleep for up to three years, which is a survival mechanism for when they sense the need to self-preserve.

Consider the habitats of green iguanas: Central America, South America, Caribbean islands, and now South Florida. What are the similarities between these locations? They are extremely warm and enjoy sunny days all year. To survive, iguanas require high temperatures. As a result, iguana populations in central and northern Florida are small. It simply does not get hot enough. The weather in the Miami area, as well as the Keys, is ideal for iguanas. They also require direct sunlight to survive. That's why you'll often see them out in the sun.

Whale sharks can neither chew nor bite as they are filter feeders. And their mouths can stretch up to 4 feet wide, but their teeth are tiny, and hence they can only eat planktons and small shrimp fishes by using their gills. Sharks can process 6,000 liters of water an hour through their gills. This shows how laborious it is.

Adult cats, like some humans, do not have enough lactase enzyme to digest lactose from milk, causing them to vomit, have diarrhoea, or become gassy. Cats only have enough of that enzyme when they are born and during their first few years of life.

These fluffy little critters, as harmless and cute as they appear, aren't as innocent as you believe! Squirrels have a habit of chewing on objects, but mix this with electricity wires and you've got a recipe for disaster. Squirrel-caused blackouts, on the other hand, are considerably easier to repair. But, let's face it, one squirrel can only cause so much harm. Because there is usually just one wire to replace, these blackouts are substantially less than those produced by storms.

Green iguanas can live for a very long time. They live an average of 9 years in the wild. Iguanas can live for up to 20 years in captivity if properly cared for. They not only have a long lifespan, but their bodies can also be very long. Male iguanas can reach 6 feet in length, while females are typically a little smaller.

Fairies formerly rode Corgis like cowboys ride horses, according to Welsh mythology. The sprites allegedly enjoyed using the little canines to pull their carts and carriages around, and they would occasionally ride the dogs into combat. The fairies gave the Corgis to human offspring, which is how the dogs got into the mortal realm, according to most versions of the account.

This habit has numerous functions: it helps cats scale back their scent so they may escape predators, it cools them off, it improves blood flow, and it evenly distributes natural oils over their coats, enabling them to remain warm and dry. Grooming is also a symbol of affection between two cats, and saliva contains enzymes that act as a natural antibiotic for injuries.

Roaches will consume any organic stuff. Human food, dead insects, cloth, paper, hair, glue, and wood are their favorite foods. Almost anything and everything, indeed! Isn't it true that cockroaches never run out of food? They enjoy both meat and sweets. You'll be surprised to learn that cockroaches can go for weeks without eating!

Because iguanas are reptiles, they thrive in water. They are fantastic swimmers. They are capable of swimming in both saltwater and freshwater. They can also hold their breath for up to 15 minutes if the water temperature is just right.

Because of their flexibility and the fact that their heads are only attached by one socket pivot, these birds can rotate their heads almost completely around. Researchers at Johns Hopkins University discovered that owls have backup arteries, which allow them to continue receiving blood and nutrients even when their blood vessels are severed while turning.

Flamingos are fascinating birds that bend their legs at the ankle rather than the knee. They basically stand on tiptoe. Their knees are covered in feathers and are closer to the body. This distinguishes them from other migratory birds.

When necessary, iguanas can detach their tail from their body. This could occur when they are picked up by their tail, become stuck, or are stepped on. This is a survival mechanism that allows iguanas to avoid predators. Tails usually snap cleanly off at the vertebrae. If this occurs while the iguana is still young and growing, its tail will most likely regrow. However, if the tail is improperly removed or the iguana is too old, it may never regrow its tail.

Boxers may have the most spectacular punches, hooks, and uppercuts on the globe, but the mantis shrimp has the world's quickest punch. When a shrimp strikes at roughly 50 mph, its small fist of wrath "accelerates quicker than a.22-caliber bullet," according to Science. The story of one such little smasher was related by National Geographic, which explained that "in April 1998, an aggressive creature named Tyson blasted through the quarter-inch-thick glass wall of his cage." He was quickly subdued by frightened personnel and sent to a more guarded prison in Great Yarmouth.

Many animals can anticipate earthquakes with varied degrees of effectiveness. Snakes, on the other hand, are the most dependable, feeling earthquakes from as far as 121 kilometres away. What's more astounding is that they can detect an earthquake up to five days before it happens! When snakes detect an earthquake, they frequently abandon their nests, even if the weather is too chilly.

Pandas eat nothing but bamboo, which is also extremely difficult to digest. That means these adorable animals must consume approximately 30 pounds of the stuff each day in order to obtain adequate nutrition, defecating approximately four-fifths of what they consume (and even what they do digest is not especially easy on their gastrointestinal system). These guys should seriously consider changing their diet.