Can anything be done to prevent these guys from digging holes behind lake walls other than either shooting them or trapping them? I feel like we are all having to put concrete mix in muskrat holes all along the walls on our 22 acre pond.

Right now we have the lake down 4'-6' to work on walls and docks and you can see holes in the bottom of walls where they have come in from the bottom to get in the yard. There's probably not enough cement in town to fill them all in (just kidding but you know what I mean).