As a kid we used to trap some muskrats. We staked a trap and set the trap in the water at the entrance hole. In high school we tried to kill fox by poring water down the hole, then gasoline so it wouldn't sink into the dirt but float on top and then we threw a match in. We never got any fox but the fire blast coming out of holes all around us was exciting. I had a friend who's pond dam was collapsed by muskrats. I don't know what he did about the muskrats but he used dynamite to blow up fox holes. I remember him saying he blew up a fox hole and the fox hit the ground running.

I'm probably the only one on the forum that depends on muskrats for some pond control. They come in and thin out my spatterdock lilies and leave. And they stay at the far end of my pond which doesn't cause any problems for me. Where they dig, some times collapses and makes small coves where minnows like to hang out. One strange thing I saw muskrats do is swim across my pond and goes into my tall Bison grass, bundle it up and swim back across the pond with good size bundle in their mouth. They had plenty of plants to eat in the pond so the only thing I could figure was they might be lining their holes with the grass.