Entrance to chipmunk burrow
Overview
Chipmunks are small ground-dwelling squirrels. In Missouri, the species is Tamias striatus or the Eastern chipmunk. It is identified by five dark brown stripes separated by creamy buff-colored stripes, and a flattened dark tail. Although chipmunks rarely cause enough damage to warrant control, there are occasional conflicts with gardeners and homeowners.
Symptoms and Diagnosis
Chipmunk damage is generally caused by their tunneling and digging activity resulting in holes in lawns or gardens; or slumping and water damage to patios, driveways or foundations. Their foraging activity may destroy garden plants, especially young seedlings or bulbs. Chipmunks may become a nuisance when they enter buildings.
Life Cycle
Chipmunks dig an elaborate burrow system consisting of a 2 inch diameter vertical tunnel that extends down about 10 inches, turns and goes 20 to 30 feet, leading to a chamber that is about 12 inches wide by 6-8 inches tall. This chamber is used as a storehouse and may contain as much as half a bushel of nuts and seeds. Nesting material is placed over the food and this chamber will be used for hibernating and raising young from late fall until late winter. Eastern chipmunks have two litters of two to five young two times a year, in late winter and again in early summer. Chipmunks are omnivorous eating a variety of foods including seeds, nuts, berries, mushrooms, insects, worms, and bird eggs.
Integrated Pest Management Strategies
1. Do nothing. Chipmunks are part of the natural landscape and may be valued for their antics as well as their role in aerating soil, dispersing seeds and as a food source for other wildlife.
2. Close holes in foundation walls and other ground level openings if chipmunks are entering buildings.
3. Remove food sources such as pet food bowls or bird seed and reduce attractive habitat sites such as rock piles or fallen logs.
4. Live trap chipmunks if the population is overwhelming. Bait the trap with peanut butter, nuts, sunflower seeds or oats. The chipmunks need to be released at least a mile from the capture area. Released animals may not survive especially if captured at the end of the growing season when they are being moved away from their winter cache. This may be a temporary solution as other chipmunks will move into the area.
5. Use a rat trap with bait similar to the live trap. This method will kill the chipmunk and although chipmunks are protected, they may be controlled in this manner when they cause property damage.
6. Poisoned baits are not recommended since chipmunks are a food source for other animals. Using a firearm to control chipmunks may be forbidden by local ordinances.
Organic Strategies
Strategies 1, 2, 3, 4, and 5 are strictly organic approaches.