The BBC ran a special program a couple of weeks ago called "Snow Watch" which was all about how the animals survive the extended snowy weather we had this winter in the UK.
One of the questions asked was how do underground animals such as moles and voles manage when the ground is frozen. The answer given was that these animals get about by tunneling through the snow.
We were amazed today to see evidence of this whilst clearing up in the garden. There is a network of paths across the lawn leading to/from holes in the ground.