I've never seen one go back underground, but I have watched both voles and chipmunks pull plants that they have chewed into a gap in my stone wall. Carol Wallace Editor Virtually Gardening Manager, Garden Center Senior Managing Editor, Check out our Sharing Gardens and Homes E-zine Acting First Lady to SQS President of the World. Mammal Lily Eater problem Sounds to me like you got gophers. Moles usually don't eat plants. They like worms and caterpillars.
Gophers are another threat altogether.
They eat your plants from underground and they are relentless about it. In fact, I have something tunneling in my yard. Last year, I found piles of bean leaves where they ate the roots and stems and left the leaves on top of the ground. This year, so far, they haven't really eaten anything but they leave tunnels where my root systems are having problems passing deep into the soil. I have tried baits to no avail.