Prevention, identification, and control of wildlife damage are becoming an increasingly important part of home landscapes. As more people move into areas previously used for agriculture, people and wildlife merge. People need to learn to deal with wildlife so that they can prevent or minimize wildlife damages to fruits, vegetables, flowers, trees, shrubs, and lawns. The Eastern Chipmunk is one of the most common wildlife nuisances encountered in the home, yard, and garden. It is very important to gain a good understanding of its habitat, biology, and damage before any effective prevention and control measures can be used. Consult your local Division of Wildlife office, Ohio Department of Natural Resources for permits, legal status of animals, and control methods.
Figure 1. The Eastern Chipmunk (Tamias striatus)
Biology and Habitat
The Eastern chipmunk is a small, brownish, ground-dwelling squirrel (Figure 1). It is typically 5-6 inches long and weighs about three ounces. Chipmunks are easy to distinguish. They have short, pointy heads marked with two white stripes, one above and one below the eye. They also have five black lines with white striping down the back. They sit upright and hold food with their front feet.
The Eastern chipmunk typically inhabits mature woodlands and woodlot edges, but they are also found in and around suburban and rural homes. The home range of a chipmunk may be up to 1/2 acre, but the adult only defends a territory of about 50 feet around the burrow entrance. Chipmunks are most active during the early morning and late afternoon. Chipmunks favor areas with stone walls or rotting logs and heavy ground cover. They burrow, but excavate the soil, so tunnel entrances are well concealed.
With the onset of cold winter, chipmunks enter a restless hibernation and are relatively inactive from late fall through the winter months. They do not enter a deep hibernation, but rely on the cache of food they have brought to their burrow. Most chipmunks emerge from their hibernation in early March. Eastern chipmunks mate twice a year, first during early spring and again during the summer or early fall. Two to five young are born in April to May and again in August to October. Adults may live up to three years.
Chipmunks are omnivores. Their diet consists primarily of grains, nuts, berries, seeds, mushrooms, insects, and salamanders. Chipmunks also prey on young birds and their eggs. They hoard food for the winter by carrying it in special cheek pouches. A valuable forest inhabitant, chipmunks move seeds around for tree regeneration, and they are an important food source for birds and other mammals.
Damage and Damage Identification
Chipmunks may consume flower bulbs, fruits, seeds, and seedlings. When present in large numbers, they can also cause structural damage by burrowing under patios, stairs, retention walls, or foundations. Most often chipmunks are simply a nuisance problem.
Damage Prevention and Control
Chipmunks are not protected by federal law, but state and local regulations may apply. Exclusion, habitat modification, repellents, trapping, and shooting are possible means of dealing with chipmunks. Use 1/4 inch mesh hardware cloth to exclude chipmunks from gardens and flower beds. Place bird feeders at least 15-30 feet away from buildings so spilled bird seed does not attract and support chipmunks.
Landscaping features such as ground covers, trees, and shrubs, should not be planted in a continuous fashion connecting wooded areas with the foundation of the house. They provide protection for chipmunks that may attempt to gain access to the home. It is also difficult to detect chipmunk burrows that are adjacent to foundations when wood piles, debris, or plantings of ground covers provide above-ground protection. Reduce the attractive cover or nesting sites to discourage their reproduction.
Trapping is the most practical method of eliminating chipmunks in most home situations. Trapping with wire mesh traps or common rat snap traps can be used to catch chipmunks. Common box trap models include the Tomahawk (Nos. 102, 201) and Havahart (Nos. 0745, 1020, 1025) traps. A variety of baits can be used to lure chipmunks into box traps, including peanut butter, nut meats, pumpkin or sunflower seeds, raisins, prune slices, or common breakfast cereal grains.
Place the trap along the pathways where chipmunks have been seen. The trap should be securely placed so there is no premature movement of the trap when the animal enters. Trap movement may prematurely set off the trap and scare the chipmunk away. A helpful tip is to prebait the trap for two to three days by wiring the trap doors open. This will condition the chipmunk to associate the new metal object in its territory with the new free food source. Set the trap after the chipmunk is actively feeding on the bait in and around the trap. Live traps can be purchased from local hardware stores, department stores, pest control companies, or rented from local animal shelters. Check traps frequently to remove captured chipmunks and release any nontarget animals caught in them. Avoid direct contact with trapped chipmunks since there is a risk of disease transmission or being bitten. Euthanize captured chipmunks by placing them in a carbon dioxide chamber.
Transporting and releasing box-trapped chipmunks several miles from the point of capture could be another option, if it is legal in your area. However, relocated chipmunks will likely seek out a familiar environment and cause a problem for someone else. In addition, there is also the risk of introducing a diseased animal into a healthy population. Last but not least, relocating a stressed animal into the wrong habit will often make them more susceptible to predation and diseases.
Common rat snap traps, glue boards, and Sherman traps, can be used to kill chipmunks if these traps are isolated from children, pets, or wildlife. They can be set in the same manner as live trzaps but hard baits should be tied to the trap trigger. Prebait snap traps by not setting the trap until the animal has been conditioned to take the bait without disturbance for two to three days. Small amounts of extra bait may be placed around the traps to make them more attractive. Set the snap traps perpendicular to the chipmunk’s pathway or in pairs along travel routes with the triggers facing away from each other. Set the trigger arm so that the trigger is sensitive and easily sprung. To avoid killing songbirds in rat snap traps, it is advisable to place the traps under a small box with openings that allow only chipmunks access to the baited trap. The box must allow enough clearance so the trap operates properly. Conceal snap traps that are set against structures by leaning boards over them. Small amounts of bait can be placed at the openings as an attractant.