Need advice

We just moved into a new house with a fenced backyard...so for the first time Kermie can go out by herself without a leash. Well, the silly pup has taken to digging up a corner of the yard!! She "roots" around then pulls up the long grass roots, pulls them out, and runs around with them (like they are sticks or something!) but she has left the one corner basically with no grass. I just went out there and it looks like you can lamost see the bottom of the fence. Any advice on how to curb this behavior would be appreciated!!!