we are a bit rats

Humans are a bit of a rat.

I'm not calling anyone stingy;

the meaning of the phrase is literal.

For millennia, humans and rats have had a very close relationship and it is not by chance.

They immediately settled in our cities, we have chosen them as a model in research and there are even those who have them as pets.

In anthropozoology, the science that analyzes the interactions of human beings with animals, every relationship has an explanation.

In this case, it is largely because we look alike.

As the saying goes, “tell me who you're going with and I'll tell you who you are”.

The first thing we must clarify is what we mean by rat.

There are many species of animals that could fall into this category, but those that have coexisted with humanity are basically two: the black rat (

and the brown rat

).

Above all, they are distinguished by size.

If it's a large rat roaming the gutters, it's probably a brown rat, but if it's a smaller rat scampering between the shingles of a house, it's probably a black rat.

Every relationship has a first encounter, a beginning.

and

rats do not come from the same place: we come from Africa and they from Southeast Asia.

So we had to explore new territories to meet them.

Soon, these rodents discovered that life with us was better, and they settled in the cities without our consent.

From then on, they no longer separated from us and followed us on our migrations, colonizing the rest of the world.

In 2017, a large-scale study analyzed the genes of 110 brown rats from around the world and found that they arrived in Europe 1,800 years ago.

Humans are a very flexible species, prepared to live in different environments, from the desert to the coldest corners.

Being able to follow us is not something that any species can do.

Like us, rats adapt to whatever is needed and, as an invasive species, when they arrive in a new place they extinguish the native species of the area.

Part of their success is due to the fact that they eat everything.

They have an omnivorous diet and that is why they feel so comfortable among our garbage.

Both fruit peelings and fish remains, they devour everything with greed.

Here we find the source of the first contention: we compete for resources, so conflict is inevitable.

They destroy our crops and barns eating what we consider ours.

In addition, they became an important transmitter of diseases.

There is nothing more to remember than the great tragedy that was the famous black plague, which during the fourteenth century killed more than a third of the population of Europe.

This is a rodent disease caused by a bacterium (

) that can be passed to people by fleas.

Typhus is transmitted in the same way, caused by another bacterium (

), which had much to do with the defeat of Napoleon during his invasion of Russia in 1812. Clearly, rats have affected the course of history.

Despite our efforts to eradicate them, rats remain in our cities.

The New York authorities have been fighting them for 355 years to no avail, because they are highly intelligent animals that learn to avoid poison and traps.

Desperate, in 2017 New Yorkers spent 32 million dollars (almost 30 million euros) on a special plan to eradicate them, but the population continues to grow.

The problem is that, even if they manage to kill 90%, the extermination programs are useless since the rats reproduce very quickly.

Especially if they have food to spare, because there is less competition.

These defeats are a humbling cure that reminds us that we are not in control of the world.

The rat 'Magawa' was decorated in 2020 in the United Kingdom for his work in detecting antipersonnel mines.

His work in Cambodia has cleared almost 141,000 square meters of land, the equivalent of 20 football fields, of mines.

In the mid-19th century, our relationship with rats became more complex.

They not only complicated our existence, they also began to save millions of lives.

It was the first animal domesticated for scientific purposes.

They were ideal because they were readily available in our cities and they reproduced quickly.

However, they would not have been a useful model were it not for their resemblance to us.

Rodents are the largest group within the class of mammals, making them good representatives.

Although they may seem different at first glance, much of what goes on behind the curtain is physiologically very similar.

In turn, humans are the most intelligent primate and the intellectual acumen of rats continues to amaze scientists.

Although in recent years another species, the laboratory mouse, has been replacing it in fields such as biomedical research, the rat is still the queen in the field of psychology and cognition.

It turns out that their brain connections are surprisingly similar to ours.

We still need to comment on one last fundamental similarity, for which the door has been willingly opened to them in some homes: they are extremely social.

They have great empathy and can form bonds even with us humans.

Despite what many think, rats are very clean and spend much of the day grooming themselves.

They learn tricks like dogs and if you train them, they come to meet you when you call their name.

Despite the bad reputation, all these qualities are making them increasingly popular as pets.

It is not surprising that we find similarities between a primate and a rodent since, after all, evolution is full of convergences.

Bats and birds fly through the sky, dolphins and sharks have taken to the water and humans and rats to the cities.

With their long tail, pointed snout and small eyes, we don't exactly identify with them, but don't judge a book by its cover: what's important about the rat is on the inside.

Laura Camón

is a biologist, primatologist and science communicator.

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