They use the branches and logs to make dams, canals, and lodges. When the water is deep, beavers build lodges with mud, rocks, and sod. A typical lodge is 10 to 20 feet around and 6 to 8 feet above the water. Beavers live in colonies. There are 3 families in a colony.
Beavers are engineering geniuses, building both dams and lodges during their busy lifetimes.
Dams slow down the speed of rivers and streams so that stable lodges, built of mud and branches, may be built to house the beaver family. Because the lodge is underwater, the temperature inside during winter is considerably warmer than that of the outside air. When water backs up behind the dam beavers have built, a pond is born which provides wetlands habitat for many other animals such as ducks, geese, fish, reptiles and amphibians and the predators that feed on these creatures.