Ground squirrels and chipmunks are burrowing rodents that eat seeds, nuts, fruits, roots, bulbs, and other foods. They are similar, and both are closely related to squirrels. They tunnel in soil and uproot newly planted bulbs, plants, and seeds. Ground squirrel burrows run horizontally; chipmunk burrows run almost vertically.
Traps: Bait live traps with peanut butter, oats, or nut meats. Check traps daily.
Habitat modification: Ground squirrels and chipmunks prefer to scout for enemies from the protection of their burrow entrance. Try establishing a tall groundcover to block the view at ground level.
Other methods: Place screen or hardware cloth over plants, or insert it in the soil around bulbs and seeds. Try spraying repellents on bulbs and seeds.
Mice and voles look alike and cause similar damage, but they are only distantly related. They are active at all times of day, year-round. They eat almost any green vegetation, including tubers and bulbs. When unable to find other foods, mice and voles will eat the bark and roots of fruit trees. They can do severe damage to young apple trees.
Barriers: Sink cylinders of hardware cloth, heavy plastic, or sheet metal several inches into the soil around the bases of trees. You may be able to protect bulbs and vegetable beds by mixing a product containing slate particles into the soil.
Traps and baits: Some orchardists place snap traps baited with peanut butter, nut meats, or rolled oats along mouse runways to catch and kill them. A bait of vitamin D is available. It causes a calcium imbalance in the animals, and they will die several days after eating the bait.
Other methods: Repellents such as those described for deer may control damage. You can also modify habitat to discourage mice and voles by removing vegetative cover around tree and shrub trunks.
In some ways, moles are a gardener’s allies. They aerate soil and eat insects, including many plant pests. However, they also eat earthworms. Their tunnels can be an annoyance in gardens and under your lawn. Mice and other small animals also may use the tunnels and eat the plants that moles have left behind.
Traps: Harpoon traps placed along main runs will kill the moles as they travel through their tunnels.
Barriers: To prevent moles from invading an area, dig a trench about 6 inches wide and 2 feet deep. Fill it with stones or dried, compact material such as crushed shells. Cover the material with a thin layer of soil.
Habitat modification: In lawns, insects such as soil-dwelling Japanese beetle grubs may be the moles’ main food source. If you’re patient, you can solve your mole (and your grub) problem by applying milky disease spores, a biological control agent, to your lawn. This is more effective in the South than in the North, because the disease may not overwinter well in cold conditions. However, if you have a healthy organic soil, the moles may still feed on earthworms once the grubs are gone.
Other methods: You can flood mole tunnels and kill the moles with a shovel as they come to the surface to escape the water. Repellents such as those used to control deer may be effective. Unfortunately, repellents often merely divert the moles to an area that is unprotected by repellents.