Fact or Fiction | Amazing facts about animals: exceptions to the rules

Female armadillos can control pregnancy. If the environment is unfavorable for the female, she can delay the development of the embryo for up to 2 years.

Scientists have found that other animals can also pause pregnancy. For example: certain species of kangaroos and wallabies, bears, seals, many rodents, deer, and anteaters. In total, there are over 130 such mammal species.

Embryonic pause in these animals can be related to hunger, stress, seasonal reproductive cycles, or the fact that the female has not finished nursing previously born offspring.

There are creatures that never sleep, and we see them almost every day — ants. Although the lifespan of an individual ant, whether it's a worker or a soldier, is short — 7–10 days, during their entire brief life, they never once doze off.

However, recently another opinion has emerged. Videos have been presented showing ants in a static state for several tens of seconds. They literally freeze in place, even tilting their heads, and their antennae stop moving. This has led to a new hypothesis that the ant's brief pause is actually its sleep.

Not all animals have red blood. Insects have white or colorless blood, while mollusks have blue blood.

The icefish, or white-blooded fish, has semi-transparent blood that appears whitish. But how does the icefish survive without oxygen and hemoglobin — the respiratory enzyme? Physics comes to the rescue: in cold water, as we know, more oxygen is dissolved than in warm water, and the icefish takes advantage of this. Almost eliminating gills as a source of oxygen, it switches to cutaneous respiration. Consequently, its circulatory system has changed: capillaries on the body surface are more densely distributed, and its heart is three times larger than that of other fish.

The very small Turritopsis dohrnii jellyfish lives forever. It has a bell-shaped form with a maximum diameter of about 4.5 mm. It is found in all oceans in temperate and tropical zones.

After the reproductive process, this jellyfish begins to revert to its earlier developmental stage. In simpler terms, it rejuvenates, transforming from a mature individual back into a polyp, and repeats the entire cycle — and so on infinitely. Only an accident or a hungry predator can break this chain.

Turritopsis dohrnii is the only known species capable of returning to its initial polyp stage. This happens through a special transformation process that requires specific types of cells. In experiments, it was discovered that the jellyfish at any stage of life can transform back into a polyp: during hunger, rapid temperature changes, decreased salinity, or bell injury. Moreover, this cycle can continue indefinitely due to unique genes, which are twice as abundant in this jellyfish species as in other species.

The Mozambique spitting cobra is dangerous even at a distance. It is known for its ability to spit venom with remarkable accuracy. If its venom gets into the eyes, it can cause impaired vision or blindness.

This snake is widespread in Eastern and Southern Africa. It is mostly active at night and feeds on frogs, lizards, small mammals, and locusts. When threatened, it inflates a wide hood and can eject venom.

It is one of the most dangerous African snakes. Moreover, it is very nervous and aggressive. 94% of human bites occurred in human settlements, of which 82% were bitten while sleeping. As a result of the bites of the Mozambique cobra, only a few people have died.

Not only can fish walk on land, but they can also jump, using a strong tail. Of course, not all fish, but only one species — mudskippers. They are notable for being able to temporarily live in the open air, where they feed on insects and small invertebrates.

Mudskippers inhabit mangrove forests and brackish waters of tropical coastlines. During high tide, they crawl out onto land and, using strong pectoral fins, scuttle along the shore quite briskly. They can go a long time without water, storing it in their large mouths.

These fish forage for food during low tide. Their thickened pectoral fins resemble arms and are used as support for movement, and during high tide — even for climbing trees.

Cats can retract their claws into the pads of their paws, becoming temporarily "soft and fluffy". They do this because they hunt from ambush and do not need any extra noise.

But there are cats that do not do this — they cannot. These include cheetahs — the fastest among the feline family and the least similar to their relatives. In addition to the cheetah, fishing cats, Sumatran, and Iriomote cats also cannot retract their claws.

Find more interesting facts about cheetahs in our article ☛

Find more interesting facts about fishing cats in our article ☛

Palaeontologists have long known about the existence of three-eyed vertebrate animals in the past, and only one species has survived to the present day — the tuatara (or Sphenodon), a beak-headed lizard living on archipelagos near New Zealand.

Externally, it resembles a dragon hatchling, only without wings. And indeed, there is a third, parietal, eye located on the top of its head. It doesn't see very well — barely distinguishing day from night, but it is a real eye, and tuataras use it to observe the sun. The third eye participates in synchronizing the body's daily rhythms with the day and night cycle, in ensuring the animal's spatial orientation, and in thermoregulation.

In addition to humans, another creature can stand on its head — the elephant. A human, having mastered this acrobatic trick, decided to teach it to the elephant.

It's strange that the first trainers decided that the elephant was best suited for this. However, now in the circus, we can observe an elephant weighing several tons standing tail up.