This video from Cornell in the USA says about itself:
23 September 2015
In recent years, beavers have taken up residence in Sapsucker Woods Sanctuary, home to the Cornell Lab of Ornithology in Ithaca, New York. Beaver activity on Sapsucker Woods Pond has caused some problems, so we turned to Beaver Solutions LLC to help us tackle the issue. The device installed in the pond will allow us to coexist peacefully with the beavers!