I have a large backyard that borders an open field. At night some type
of digging rodent(s) come under the fence and dig up bugs in my lawn.
While natural, it leaves holes in the lawn and holes under the fence.

Problem is that the land drops off past the fence, so am lookiing for
a cheap way to put down some type of barrier along the back. Yes, have
put down bug killer to lessen the food supply, but need a permanent
solution.

Cannot afford a retaining wall or sunken stone wall, and with the drop
off, don't know if it would hold anyway. ONe more thing - sprinkler
line runs along same fence.

Anyone have a economica, viable, solution?