Moles

In rural areas especially, moles can cause great damage to your garden/land by tunnelling through the soil, up to ……inches below the surface. 
With heavy infestations, the ground can become unstable and holes may appear not only damaging the foundations of your land but also creating safety risks.
Moles tunnel using their large two front paws to scrape away the earth and feel along tunnels with their snouts and whiskers. 
Because of the absence of light within their living conditions, moles have very poor eyesight so very rarely will you see mole activity above ground. For more information read here and here