Beaver are the most interesting animals we see in Canada. I have seen huge dams that they have built. They have lots of lodges (homes) around the different islands, where you see the whole family swimming around. They are often on shore, eating the bark off of sticks and logs. I used to take beaver sticks home to my kids.  When we catch them swimming they will give you the 'tail-slap' - like in this video. When you get too close, they make a big splash with their tail and dart away under the water in a different direction. It is a cute defense mechanism.