Eastern moles often excavate large amounts of dirt, which form mounds. This is done so the mole can go deeper to find food. In areas like this the tunnels are sometimes harder to find because of their depth.

As you see here, even a little frost does not stop gophers from looking for food. As long as the tubers they eat aren't frozen they will keep collecting food. They often collect food and store it in caches located underground.

Voles eat the grass as new shoots grow out of the soil. Here you can see the dead areas which look like trails. These trails are often very visible after snow melts in yards and the grass is recovering.