Muskrat damage usually comes in a few ways. They can damage natural pools & ponds by burrowing into the banks. These long burrows destabilize the bank structure and threaten boathouses, docks and other structures. Passerbys can turn an ankle or knee very quickly while walking over them as the ground surface is unchanged but putting weight on that area will cause it to cave in and your feet with it. Muskrats also damage levees, dikes, canals and earthen dams in the same way. Large populations of muskrats will clean a landscape quickly of ornamental or natural vegetation.