Chipmunk

Common name: Eastern chipmunk
Scientific name: Tamias striatus

Biology
Adult body length (without tail): 5 to 6 inches
Adult body weight: 2 1/2 to 3 1/2 ounces
Gestation period: 29 to 31 days
Litters per year: 2
Litter size: 2 to 8 young (usually 2 to 5)
Breeding season: April through May and August through
September
Birthing season: May through June and September through
October
Age at which young are weaned: 4 to 7 weeks
Activity period: Daytime
Range: 1 acre or less
Primary foods: Seeds, acorns, nuts, fruits, plant bulbs, tubers

Pest status
Chipmunks in urban settings often dig up and eat newly planted garden seeds and flower bulbs. Strawberries, plums, apples and other cultivated fruits are gnawed for their flesh or for their seeds. They commonly dig unsightly burrows in lawns and flower beds in which to nest. Costly damage may result when chipmunks excavate burrows along building foundations, beneath poured cement porches, patios and walkways. Gradual collapse of the excavations lead to the formation of stress cracks in cement slab construction, as well as inwardly sloped grade of pavement, a condition conducive to moisture drainage and retention along the foundation. Furthermore, chipmunks will nest beneath residences, sometimes gaining access to living spaces, basements and crawlspaces through utility penetrations and other structural gaps. Occasionally they take up residence in attics or other sites that are a distance above ground.

CONTROL
Exclusion
Exclusion is the best method for keeping chipmunks out of buildings and should parallel rodent-proofing measures used for rat and mouse control. Essentially this involves the closure of all openings that might allow access to buildings, including the installation of chimney caps.

Live-trapping
Rottler technicians use small live-catch, wire-mesh cage traps (16 x 5 x 5), aluminum box traps (10 x 3 x 3) and other traps of similar type and size removing chipmunks from around buildings. Traps are set in areas along pathways commonly used by the animals. Attractive baits are nutmeats, peanut butter, pumpkin and sunflower seeds and corn. If chipmunks avoid trap sets, the traps are prebaited with the doors propped open for a few days; then the traps which have attracted the animals will be re-baited and set. Prebaiting can make a trapping program more effective. Live-catch cage and box traps are checked daily so that chipmunks can be managed humanely.

Lethal-trapping
On occasion, Rottler technicians utilize rat snap traps baited with nutmeats or peanut butter due to this method's effectiveness in eliminating chipmunks from garages, basements and attics, as well as reducing chipmunk populations outdoors. Snap traps are housed in tamper-resistant housings/ stations in order to protect children and non-target animals from injury. As properties become repopulated from surrounding areas, repeated trapping may be required.