Beavers live both on land and in water. On land, beavers are very uncomfortable. The front legs of beavers are very short, so they cannot walk fast. They cannot run away from their predators on land, but in water they are excellent swimmers. When in the water, beavers swim beautifully and fast. Wolves and bears are their predators. To keep their families safe, beavers build a small home in the water, which is called a lodge. The only way to get through the lodge is to swim through a tunnel.
What if a river or stream is not deep enough to make a lodge? To adjust to this sort of habitat, a beaver will construct a dam, which holds back water to form a pond. To build this dam, they shove mud, branches and stone together to make a wall in the water. Then, they use their strong teeth to cut down trees. Beavers tend to chop down most of the trees right by the water. When they are done cutting those trees, they go back into the woods to look for more trees.
It is much easier for beavers to move a block of wood by floating it in the water than by moving the wood on land. Therefore, they dig canals in the ground, allowing water to run along the canals that connect the wooded area to their pond. The beavers use that canal to float the logs down to the river or pond. The beavers shove the freshly cut logs and sticks into the muddy ridge they created earlier. Since water cannot get past the dam, the water in the stream forms a huge pond, allowing the beaver and its family to build their lodge.
Beavers have special body structures that help them work and swim with ease. Like ducks, beavers' feet are webbed. This helps the beavers swim and move through the water. The beaver's well known flat and wide tail helps the beaver move around. They use their tails to communicate with other beavers. A beaver will sniff and listen so it knows when a predator is near, then the beaver slaps its wide, flat tail on the water to warn the other beavers so they can all swim to the water for safety. Beavers also use their tails on land sometimes. When cutting down trees, beavers stand using their tails to help them balance.
Beavers are rodents, or gnawing mammals, like squirrels and rats. Beavers have hard coatings on the two front teeth and bottom teeth. The coating keeps the teeth from breaking. There are two folds of skin behind the front teeth, which keep water from going inside the beaver’s mouth when it is biting the wood in the water. Beavers also have their own goggles inside their eyes. Both eyes have clear inner eyelids to help the beavers see under the water. They can stay underwater for almost 15 minutes, because their lungs hold an amazing amount of air. Beavers slow down their heart beat when they swim, allowing them to need less oxygen when in water. A valve in the beaver’s nose closes its nostrils while it swims. All of these characteristics help beavers live safely and happily in their habitat.
Like humans, beavers can also change their environment, to be comfortable and convenient, more than most other animals on the earth.
[Sources: STC Animal Studies; National Geographic Kids]