Michigan State University Extension
Wildlife Database - 11209803
11/20/98
Glenn Dudderar MSU Extension Wildlife Specialists
The Eastern Chipmunk, the least chipmunk and the striped ground squirrel are the smaller members of the squirrel family, measuring 8 to 10 inches. All are primarily ground dwellers, but chipmunks occasionally climb trees and shrubs for food and protection.
Chipmunks can be identified by the black and white strips on the back of their reddish brown coat and by their habit of running with their tails straight up in the air. The striped ground squirrel, erroneously called a gopher, has cream-colored strips the length of the body. Five of the 11 light stripes are broken into a series of spots. These members of the ground squirrel family move quickly and are alert to danger. Chipmunks prefer woody areas with plenty of food-producing trees and bushes. Food and protection offered by shrubs, flowers, gardens and various types of landscaping attract chipmunks, and it is in these conditions that most problems arise.
Striped ground squirrels prefer grassy areas, such as lawns and golf courses, where they sometimes create problems. Their burrows are extensive and may exceed 30 to 40 feet in length. The chipmunk burrow system usually opens at the base of stumps, fallen logs or at the side of stone walls and is kept free of excavated dirt at all times. The burrow entrances of the striped ground squirrel are usually surrounded with excavated dirt and may occur anywhere in a grassy area. These interesting creatures are often a welcome addition to the landscaping, but at times their numbers or destructive habits cause the landowner to seek damage control methods.
REPULSION
Commercial repellents containing 7.98% thiram may repel these animals from plants. Thiram sprays must be applied repeatedly in order to protect new growth. Seeds for direct seeding of forest trees can be treated with materials containing 42% thiram to avert chipmunks and ground squirrels from eating the seeds. Repellents are generally effective only as long as other foods are available in the area. Sources for these materials are listed in "Sources of Supply".
EXCLUSION
Chipmunks can be prevented from damaging shrubbery and small trees by wrapping the base of these plants with light-gauge metal. Where possible the metal should be at least 12 inches high to prevent climbing.
POPULATION REDUCTION
Trapping
The large, wooden-base snap traps used in rat control are effective for chipmunks and striped ground squirrels. Nut meats, peanut butter, oatmeal and similar foods make good baits. Place traps along runways or at burrow openings and other areas of activity. It is usually advisable to place the traps under a small box with an opening that allows ground squirrels, but not desirable birds, to get to the baited trap.
Shooting
Shooting is a most effective control method if only a few chipmunks or ground squirrels are involved. Small gauge shotguns or air-operated pellet rifles are the most desirable weapons. Early morning or late afternoon are the best hunting periods. Check with local police officials for shooting regulations.
Cats
A cat that is not overfed can keep a chipmunk or ground squirrel population in check. However, other animals, especially birds, may also be taken.
Poisoning
(These techniques require a permit from the Law Enforcement Division, Michigan DNR.)
Burrow fumigation (fumigant: gas cartridges, formulation: 3/4-3 oz.)
The following fumigant can be used to gas ground squirrels in their burrows. Cover the burrow opening with a piece of inverted sod to confine the gas to the burrow without smothering the cartridge with loose soil. Light fuse and insert in burrow. Cover burrow opening with a piece of inverted sod.
Poison Baiting
Strychnine-treated grain bait is available from the U. S. Fish and Wildlife Service for use under government supervision. Apply teaspoon quantities around burrow openings or in burrows if birds may consume bait. After 48 hours, close burrows with soil. Retreat any that are reopened. On pound will treat 10 to 15 acres.