Gophers and moles are two of the most common lawn and garden pests. Although some eradication and barrier methods work for both pests, others are specific to one -- so it's good to know thine enemy. Some simple observations will help you determine whether pocket gophers or moles are messing with your landscape.
Determine what they're consuming. Pocket gophers are rodents that eat bulbs, roots, grass and seeds. Moles are insectivores, which means they mostly eat earthworms and insects, although the Townsend's mole might devour tubers and roots.
Examine the holes left in your yard, which indicate where the moles or gophers have been excavating their tunnels. Molehills are volcano-like, with a pile of earth thrown up in the center, then rolling down the sides. Moles often dig just below the surface, unlike gophers. Gopher mounds are flatter compared to mole mounds; they're fan-shaped with an exit hole on one side. Gophers usually plug their holes; moles usually don't.
Try to catch a glimpse of your yard pest -- although this is awfully hard. A mole has a short, velvety coat, a slender snout, paddle-like paws for digging, no visible ears and small teeth that are like needles. A gopher has large incisors that extend outside its mouth, smallish eyes and ears, and fur-lined cheek pouches used for carrying food -- thus the name pocket gopher.