Moles live underground and are hard to spot, but the damage they leave behind can alert homeowners to their presence; moles leave behind molehills when tunneling, according to The Gopher Guy. Trails of surface tunnels along a driveway, lawn border or foundation may signify mole problems.
Moles excavate when they are not foraging for their favorite underground food: earthworms. When they excavate, The Gopher Guy notes that they push dirt straight up from the ground, and this action results in mounds that are volcano or conical in shape and that may be of different sizes.
Moles are generally considered pests because they prefer landscaped areas where the soil is usually rich with nutrients and kept moist due to irrigation or watering, both characteristics of soil where insects and worms thrive. Moles are generally active year round and create mazes of tunnels below the surface that provides them with natural protection from predators and other threats, including freezes and droughts. Moles can tunnel at a rate of 15 feet in an hour; in favorable soil, they can tunnel even faster, digging shallow tunnels at a speed of up to 12 inches in a minute, according to the Washington Department of Fish and Wildlife.