Thursday’s column identified China as the most dammed country. Another dam builder is the beaver. Their dams, canals and lodges protect them from predators, provide a food source and building materials. When startled, beavers initiate an alarm on their quiet pools by energetically smacking the water with their broad tail; forwarding a danger message to others. Stockpiled sticks provide a winter food source and a means of insulation. Snow pack prevents water from freezing around their homes. Often, the removal of existing beaver dams causes flash flooding of residential areas. In the protection of their habitat, conservation groups note that the beaver also assists humans by preventing residential flooding and roadway wash outs.