The kits, as many as eight, are born in mid-May or early June. They stay in the family unit for two years before leaving to establish their own territories. All family members help look after the kits and bring them solid food while they are being weaned from the mother, a period of three months. The adult male has a strong paternal sense. If a kit falls into a floor entrance before it is ready to swim, the father is often the one to rescue it with a nudge back to the safety of the lodge chamber.
Beavers are the largest rodents in North America.
A fairly recent ancestor of the beaver, living about two million years ago, was a giant species the size of an American black bear. Because of the quality of their pelts, beavers were nearly exterminated from the United States by unregulated fur harvests in the 1800s. Their populations have recovered and stabilized as a result of trapping restrictions and reintroduction into suitable habitat. Beavers are present in all of Maine. They feed at night, preferring aspens, poplars, willows, alders and birches less than fifteen years old.