They may also remove some sticks from the dam to lower the water and create air space under the ice. Beavers fell trees to get at the higher, newer, more succulent growth. After eating, the beavers gnaw the trees into pieces which are then used in building dams or lodges. Small trees are eaten more completely than larger, woodier ones. Beavers cannot cut trees and make them fall in a certain direction.
Beavers build dams on streams and creeks.
This building behavior appears to be instinctive rather than learned. A dam backs up a barrier of water around the beaver's home lodge, much like a moat around a castle. Dams require periodic maintenance, especially after heavy rains and during snow melt. For shelter and rearing young, beavers construct lodges. These are dome-shaped islands of sticks and logs plastered with mud.