Why beavers build dams? Beaver Secrets

Everybody is aware that beavers are the best builders ever: they create such perfect dams from fallen trees that even experienced hydro techniques get jealous of their constructions!


Beavers are always busy with building in order to make the way to their homes easier, as they are usually located by the waters with fast current. By separating the waters with tall walls constructed from couple of trees and huge amount of branches, beavers weaken the current (by creating a backwater) which makes it safe for them to reach the hut unnoticed by the hunting varmints, where they can also store safely rich sources of food.

By building such artificial ponds with the help of dams, beavers create perfect environment for growing bog vegetation amidst the backwater. Such plantations of rich green foods become a great base for the daily balanced meal of these animals.

beaver at work

beaver at work

Beavers construct the dams by gnawing at the base of the trees and after the animals makes such cuts the tree falls down and forms a foundation of the dam. Besides large trees, beavers also use the smaller sized trees for dam construction. They strengthen the dam with the help of branches, stones and clay.

Once the dam is finished, beavers can start building their hut. Beaver’s hut is a real engineering construction, even though from the outside it looks like a pile of branches. It is built from the ground and branches only. By using clay and trees branches, beavers construct the hut in such way that it can be entered only by the other beaver. So the size of the entrance of the hut is strictly regulated by the beaver himself during the construction process.

The hut looks like a cone-shaped brush pile, sticked together with ground and clay, with a height of 1-3 meters and diameter of 10-12 meters. There is a small space on top of the hut for letting in fresh air and light.

beavers dam
The entrance to the hut can be found in the depth, where the water doesn’t freeze even in severe weather. Inside the hut looks like a chamber with a height of 40-50 centimeters and one meter wide. There is a lie place at the bottom of the hut, covered with wood chips, twigs, fur and dry grass.

Beavers sleep, store food and bring up the small beavers inside the hut. Their home also performs a protection function against the enemies and helps them to live through the cold seasons.

Another amusing fact: the record for the longest constructed dam belongs also to beavers, living in South America. Especially massive constructions can be noticed in the areas where no human traces are found to bother them. According to biologists, there was a beaver dam in one of the American reservations, which length reached 230 meters with a width of 70 meters. But even the bigger dam was found on one of the rivers on this continent. The length of this construction reached 652 meters. Such a dam is a result of work of few beaver’s generations for sure, as they needed couple of dozens of years to complete such an impressive construction.

More from ZooEarth