Beavers are one of nature’s greatest engineers and can build dams that are up to three metres high (ten feet) and 500 metres (1,640 feet) long. They busy themselves with these mammoth construction tasks for protection, as dams help to create a safe space for them to build their homes.
First they build up the riverbed using mud and stones, then pile branches and mud on top to form a dam. This creates a calm pond in which they can construct a dome-shaped home called a lodge. As they are built on small islands above the water level these homes are safe and dry, and can only be accessed by swimming through a tunnel, meaning they are out of reach to most predators.