Oftentimes, rats are perceived as annoying and dangerous pests that are difficult to get rid of – for reviews of rat poisons be sure to check out this article. However, rats are some of the most interesting animals out there. For instance, they can be used for testing tuberculosis samples, they can sniff bombs, they can laugh and show human-like emotions!
No Y chromosome
As you probably remember from your biology class in high schools, in the case of mammals, the distinction between males and females is determined by sex chromosomes. While females have two X chromosomes, males receive one X and one Y chromosome.
Yet, studies have shown that Japan’s Amami spiny rat is the one exception to the rule. In this species, males do not have the distinctive Y chromosome. Still, they do develop male sexual organs. To make their genetic pool even more curious, these rats are born with just a single X chromosome, regardless of their gender.
In recent research carried out in 2017, Japanese researchers have pointed out that these rats are sexually flexible as they are genetically capable of developing both testicles and ovaries. For scientists, the Amami spiny rat is still a very interesting subject that is under investigation.
They can be trained to detect tuberculosis
In Africa, rats are put to good use. In 2014, an African giant pouched rat called Tariq was successfully trained in a lab to correctly identify samples that were infected with tuberculosis. At that time, Tariq was the eight rat that was trained for the job.
The reason why scientists have decided to use rats for this task has to do with their rapidity when it comes to sniffing and recognizing this airborne disease. According to the specialists, these rats are highly effective as they can analyze more samples in ten minutes than a trained lab technician can evaluate in an entire day!
In Africa, the fight against tuberculosis still claims a lot of lives. In 2012, 480,000 lives were lost due to the disease. In the past, rats have also been trained by a Belgian nonprofit organization called APOPO to detect mines.
They conquered space before us
Another interesting fact about rats is that they conquered space before humans did. In 1960, the Soviet Union launched Sputnik 5, a capsule that contained two rats, a pair of dogs, a rabbit, and 40 mice.
These were the first-ever animals to go to space and to return safely. A year later after the successful return of the Sputnik 5, the Russians sent the first man into space. The two dogs that were sent to space on board of this capsule became pretty famous in Russia.
Belka and Strelka, the two dogs, were so beloved by the citizens of Russia that they actually became characters in cartoons and 3D animated films. After their natural deaths, both dogs were preserved and they are now displayed at the Museum of Cosmonautics in Moscow.
One of the offspring of Strelka, a female dog called Pushinka, was given as a gift by Nikita Khrushchev to Jaqueline Kennedy. It lived in the White House with the president and his family and, later on, had four puppies of her own that were given away.
They are carriers of diseases
The rats that live in big cities pose a great threat to the well being of the citizens because of the many diseases that they carry. As studies have shown city rats carry pathogens such as E. coli and salmonella that can cause vomiting and diarrhea. The bacteria are spread when humans come into contact with the pests themselves or with their urine, feces or saliva.
People who are exposed to rats are also more likely to suffer asthma and allergy attacks. Apart from diseases, rats are also carriers of lice, mites, and fleas. A study from 2015 showed that a city rat has around five fleas.
All people who are bitten by these pests should seek immediate medical attention as they might develop tetanus as well as rat-bite fever. Both of these diseases can be fatal when not treated accordingly.
Rats and mongooses in Hawaii
In 1883, Hawaii was confronted with a rat invasion. To eliminate the rats, it was decided to introduce mongooses. These animals are native to India and they are known as opportunistic feeders that eat, among others, rats.
However, this decision did not yield the expected results. It only made things even more complicated. Because the mongooses are diurnal animals and the rats come out of their hideaways at night, the two species missed each other.
Now, Hawaii has to deal not only with a rat problem but also with a mongoose infestation. In 1999 alone, the population of mongooses caused $50 million in damages to the state of Hawaii and Puerto Rico.
Even though they are despised by many people, rats can show human-like emotions. For instance, research from 2014 demonstrated that these pests can show regret.
Another team of researchers pointed out that these animals are not willing to make one of their own suffer just to get food. In this experiment, rats were trained to press a lever and get food. However, they stopped pressing it when they realized that one of the members of the pack received an electric shock when they did so.
What is more, it seems like rats can laugh. Of course, their laugh sounds nothing like the laugh of a human. Yet, rats do make a high pitch noise whenever they feel happy.
The tails keep them cool
Rats apparently use their tails to relieve their body heat. They do so successfully because of their ability to expand and contract the blood vessels in their tails. This is the main reason why, when compared to mice, rats do not have hairs on their tails.
When chased, some species of rats are known to shed part of their tail. As expected, tailless rats take up to one hour more to cool down. These pests also use their tails for balance whenever they have to anchor chains and climb ropes. Because of this, their tails are as long as their bodies.
Rats have many predators. A common strategy that they use is to fight using their tails. Oftentimes, rats encourage predators to hurt their tails rather than their bodies as their tails heal much faster.
On top of that, even if part of the tail of a rat gets amputated during a fight, the lifespan of the rat is not affected in any way.
They are prolific breeders
One of the reasons why rats are often an issue in the cities is because of their high numbers. Rats have managed to survive as time went on and new methods of eradicating them were developed only because of their ability to breed very fast.
On average, a female rat can reproduce once every three weeks and, each time, it can give birth to a litter of six to ten baby rats. It only takes three to four months for the baby rats to reach maturity and start breeding themselves. In the case of rats, it seems like power is in their numbers!
They like to socialize
Contrary to common belief, rats are pretty much social animals. Most of them live in communities and they like to make friends. Many of them enjoy playing and sleeping together. What is more, they also tend to get rather territorial. So, whenever an unknown rat enters their territory, the community gets very aggressive.
One fun thing to know about rats is that the collective noun that describes a group or a community of rats is mischief. It seems like the English language is biased when it comes to these very social creatures!
Their teeth keep growing
Similarly to other rodents such as rabbits, mice, hamsters or squirrels, rats also have strong incisors that keep growing. To avoid having problems masticating, these animals have to gnaw on things at all times. This is one of the reasons why they destroy everything they come in close proximity to.
To put this in perspective, annually, the teeth of a rat can grow up to five inches! Their teeth are so strong that they can chew through aluminum and cinder blocks.