This response was provided by Darryl Coates, Illinois Department of Natural Resources, District Wildlife Biologist.
Good afternoon, Chipmunks can become a problem. Listed below are several techniques. Try more than one of these listed below. Thanks for writing in.
Use 1/4-inch mesh hardware cloth to exclude chipmunks from flower beds or gardens.
Store food items, such as bird seed, dog food, and cat food in rodent proof containers.
Taste repellents work if applied to seeds, bulbs and vegetation (these products should not be used on plants used for human consumption). Products that contain bitrex, thiram, or ammonium soaps of higher fatty acids work best.
Rat size snap traps or box taps