Voles and moles can both cause significant damage to a lawn. The key differences are that moles dig underground tunnels while voles eat grass roots and trees and shrubs’ bark above the ground. Earthworms make up close to 90% of a mole’s diet. In the winter moles spend most of their time in their underground den below the frost line and will only start causing lawn damage in the spring and summer, especially after rain. The wet soil forces the worms to start making their way up to the surface and the moles will follow. Voles on the other hand stay active all winter destroying the lawn below the snow. They dig tunnels inside the snow and use leaf litter as a source of insulation.
