After mating (which takes place in January or February), the female prepares for a new litter. Two to four kits on average are born anytime from late April to June. Their eyes are open at birth and the kits are covered with soft fur. They can swim at 4 days and dive at 2 months of age. The young beavers live with their parents until they are 2 years old. Then they leave to find their own homes.
To survive, beavers must be assured of 2 or 3 feet
(0.6–0.9 m) of water year-round. Water provides a refuge
from enemies and a way to float and transport heavy
objects such as branches and logs for food and
construction. Food for winter use must be stored in
underwater food caches during autumn.