Master Builders of the Wild- Beavers at Work - BBC Earth

The beavers' survival relies on a string of dams that they painstakingly built. The beavers turn small streams into a series of deep still ponds with a plentiful food supply. The lodge is also protected from being washed away. Inside, the family take refuge from predators. Constructing this watery wonderland is an epic task. Beneath the surface, the dam is roughly three meters wide. It's a massive underwater wall built of logs and branches, reinforced with heavy rocks, mud and plants. They make their own building materials using their chisel-like teeth to fell whole trees. Finessing their masterpiece is a lifelong project. But a crucial one. Dams need to be watertight. This year's early thaw has caused a problem. The dam is leaking. The faintest trickle needs investigating and fixing. With five dams on this stretch of river, the beavers are literally beavering away. Safe indoors, the young two are honing their skills. When they reach around two years old, they'll have to leave the lodge to build dams of their own. Outside, the water is still rising. If the mountain snow melts too fast, the lodge and its kits could be in serious danger.