Beavers seem to keep the same mate for life. They mate between January and February and the babies or kits are born 4 months later. The kits weigh about 1 pound each and there may be anywhere from 1 to 8 kits in a litter. The kits stay with their parents for 2 years until a new litter is born. The kits learn to swim in the lodge within 30 minutes after they are born.
Beavers change the landscape with the dams they build.
A dam is a barrier that stops the flow of water and forms a pond or lake. These new ponds make it easier for beavers to access trees found along the shoreline. A mating pair of beavers will usually set out to find a stream where they can build a dam. They collect logs and branches in a pile to create the dam and then use grass and mud to fill in the spaces between the branches. Eventually the water will pool up on one side of the dam to form a pond.