Why do beavers build dams? About a children’s book and the truth we don’t want to hear

A child once asked me why beavers build dams. I wanted to answer smartly: to dam up water, to create a retention basin, to protect the feeding grounds… But before I could, he asked something else: And is the wolf really bad because it has sharp fangs? And it was at this point that it occurred to me that instead of fairy tales, it is worth telling children real stories. The kind that could happen in reality – for example, about a beaver that didn’t want to be the hero of a legend at all, but just needed more water to survive.

I am not an author of fairy tales. I deal with water on a daily basis – the real kind, not the symbolic kind. The one that flows in, flows out, sometimes disappears. The one in rivers, lakes and the Baltic Sea. The very real one. And that’s why I wrote about beavers. Not out of a longing for fiction, but out of a need to explain reality to children.

Because the question Why do beavers build dams? is not childish at all. It is accurate. In today’s world, rivers are often straightened for convenience, and retention is tried to make up for it with concrete. It’s worth stopping at this one scene: a beaver pulls in a branch, lays it in the water and changes the entire ecosystem. Not by administrative order, not by design. Out of instinct, out of necessity. And by the way – for the benefit of the environment.

Why do beavers build dams? is a story that could really happen. And that’s why it needs to be told to children. Without bad wolves and morals about polite animals.

Facts about beavers that sound like a fairy tale, but are true

Beavers are the only animals in Poland that design water projects without a water permit. They do not wait for an environmental decision, they do not submit applications, they do not participate in public consultations. And yet their actions bring more benefits to the environment than many a retention program.

Sound like a fairy tale? It doesn’t. This is good and responsible water management.

The European beaver(Castor fiber) is a species that was almost non-existent in Poland for decades. Exterminated for its fur, fat and smell, it returned thanks to consistent conservation efforts. And today its presence is once again changing the course of the waters. Literally. Where the beaver builds a dam, the microclimate changes, the groundwater level rises, and surface runoff is stopped.

You don’t need a measuring device to see the value of a beaver dam. Just look: floodplains are created, habitats for frogs, dragonflies and water birds. Biodiversity increases. Runoff is reduced. Water that would otherwise escape through a canal in a few minutes stays in place – sometimes for weeks.

Beaver is not acting in the investor’s interest. He is not revitalizing the creek in a concrete bathtub. He is simply doing what evolution has taught him: slowing down water, holding it back and creating space for life. And in the process, it counteracts the effects of drought better than many an expensive hydro project.

Contrary to appearances, not all beavers are the same. North America is dominated by Castor canadensis – similar to ours, but more expansive, with a different approach to resource management. In Poland, there is only the European beaver – larger, more discussing with the ecosystem. And that’s a good thing, because ours builds dams less frequently than its American cousin, but does so where it makes the most natural sense.

Why did I write a book about beavers?

Not because I wanted to make children laugh. Nor because I dreamed of creating a nice animal character to color. I wrote the book because I felt that something needed to be explained to children. Something important.

We live in a world where real nature increasingly resembles pictures from books. Rivers are sometimes straightened, streams are hidden in pipes, and wetlands are reclaimed. What should be obvious – that water is not eternal, that nature works as a system of interconnected vessels – is no longer so. For children even more so. That’s why I felt it was necessary to tell the story in accessible language, but without giving up the truth.

The book about beavers is not a fairy tale. It is a story that could really happen. In it, the beaver speaks in a human voice – this is true. But what it says is consistent with biology, ecology and hydrology. This book is not about a moral, but a starting point for discussion – with a parent, with a teacher, with oneself. Because every child will eventually ask: And how does it really work? And it’s good if he then hears the real answer.

On adult responsibility for language and message

Adults like to tell children fairy tales. That the wolf is bad because it has sharp fangs. That the river flows where we guide it. That garbage disappears when you put it in the right garbage can. And that when something is destroyed in nature, it will recover.

Meanwhile, the world does not work to the rhythm of fairy tales. And children – despite appearances – feel it perfectly. They ask accurate questions, getting right to the heart of the matter. And they have a right to an honest answer. To knowledge. To the truth.

So if we tell children that the wolf is bad – we teach them that fear justifies violence. If we say that a beaver spoils a river because it spills it – we teach that what is natural can be a problem. And if we remain silent when a child asks: Why aren’t there any more frogs in the ditch by the side of the road? then we leave them with a sense that something has changed, but without explaining why.

The language we use to tell children about nature builds their worldview for life. It is not a small thing. It is not just a word. It is the filter through which a child looks at reality.

Therefore, let’s tell the story well. Scientifically, but without exaggeration, without scaring or infantilizing. Simply – clearly, honestly and respectfully. As if we were talking to someone who might in the future become a minister of the environment, a green infrastructure designer, or someone who won’t throw garbage into a river because he once heard that a river is someone’s home.

Water education for children – why do you need to start early?

Water is transparent – literally and metaphorically. Children often don’t see it, although they have it all around them. It appears in the tap, disappears in the sink, drips from the sky, bubbles in the kettle. But rarely does anyone tell them how it all works.

In school programs, water appears as a topic – a river, a lake, maybe even the water cycle in nature. But this is not enough. Because water is not a topic – it is a condition of life. And understanding how the water environment works does not require a child to know hydrology. It is enough for him to know that if one part of the ecosystem is destroyed, the rest stops working.

And this is where the beaver can help. Because when he builds a dam, you can see the effect: the water level rises. But if you look further downstream, you will notice that birds, frogs, mud, aquatic plants appear. And then – that downstream it gets dry. And even further – that other animals have to change their place of life. It’s an ecosystem in motion. A connected vessel.

This is what environmental education is worth showing: that every decision – including that of the beaver – carries a sequence of causes and effects. And that water, though invisible, connects everything.

A felicitous punchline

Let’s tell children well about the beaver. Not as about a creature from a fairy tale, but as about a neighbor from the forest. As about a creature that has its place, its reasons, its right to be. And its engineering skills – not at all inferior to ours.

The book Why do beavers build dams? will not give answers to everything, but it is meant to be an invitation to talk, an excuse to look at the water together. To ask questions – the serious ones and the funny ones. And to learn together what is really important in nature.

Because this story is not a fairy tale. She happens every day. In Poland. Right by the river, right behind the school, right behind our house. Sometimes even in a ditch by the woods or road. Just stop and listen to the splash. Maybe it’s just a drop. Or maybe the beginning of a new story.

📘 Children’s book Why do beavers build dams?
Starting May 10, 2025, available in the online store at www.wodnesprawy.pl

PHOTO: Illustration: Ewelina Oleksiak, from the book Why do beavers build dams? (2025). All rights reserved