Beaver: Key Facts

Did you know that the beaver is the largest rodent in North America? Or that its strong front teeth never stop growing? Read on to learn more about these and other beaver key facts.

Quick Facts About Beavers

Scientific NameCastor
Physical DescriptionLarge semi-aquatic rodent with dark brown fur and webbed feet. Beavers have flat, hairless tails that they use to help them swim and slap the water if they feel threatened. They have strong, sharp front teeth coated in orange enamel; they use these teeth to cut down trees for building dams and lodges.
DistributionNorth America, Europe, Asia
HabitatWetlands, marshes, temperate forests near water sources
Average Height11 to 24 inches
Average Length31 to 48 inches
Average Weight40 to 60 pounds
Average Lifespan10 to 20 years in the wild; may live up to 35 years in captivity.
DietHerbivore; beavers eat many plant foods, including:
– Tree bark, twigs, and leaves
– Water plants
– Grasses and groundcovers
– Apples
– Human crops such as corn and beans
Number of SpeciesTwo:
– North American Beaver (C. Canadensis)
– Eurasian Beaver (C. Fiber)

What is a Beaver?

The beaver is a large rodent that builds dams and lodges out of trees that it cuts down. According to the Pennsylvania Game Commission, the North American beaver is the largest rodent found in North America.

Adult beavers weigh 40 to 60 pounds and can be up to 4 feet long. They are covered in brown fur, and they have highly identifiable flat, hairless tails.

They are known for cutting down trees with their orange teeth; they then build dams on streams and rivers to create areas of standing water for their lodges. Because of the significant impact they have on their local environments, beavers are considered a keystone species.

To learn more about beavers, check out the video below:

What are Some Interesting Facts About Beavers?

  • Beavers cannot breathe underwater, but they can hold their breath for up to 15 minutes as they swim around under the surface to avoid predators and reach the entrances to their lodges.
  • Beavers have transparent eyelids which allow them to open their eyes and see underwater. Despite this, their eyesight is rather poor.
  • Beavers’ teeth never stop growing. Gnawing on trees helps them to keep their teeth trimmed and sharpened.
  • Beaver lodges have multiple “rooms.” They build their lodges in the middle of the water to protect them from predators, and most lodges have at least two separate dens inside–one for drying off after leaving the water, and one for living in.
  • Beavers find their food mostly by smell. Because their eyesight is not very good, they have to rely more on their other senses, especially the sense of smell, for finding food.
  • Female beavers are generally larger than males. Beavers live together in families of usually 4 adults and up to 8 juveniles.
  • The largest beaver dam in the world is in Alberta, Canada. It is 2,790 feet long and is visible from space.


The beaver is a large rodent known for cutting down trees to build dams and lodges. This impressive animal kingdom engineer is considered a keystone species because of its significant impact on the environment.

If you are looking for more information about beavers, have a look at our guide about getting rid of a beaver from your yard, or the following comparisons against otter and groundhog.

Read also about other forest mammals – here are our guides about cougar, deer, ermine.

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