Trapping is the most practical method of eliminating chipmunks in most home situations. Cage-trap (wire-mesh) or common rat snap traps can be used to catch chipmunks. Common cage-trap models include the Tomahawk (Nos. 102, 201) and Havahart (Nos. 0745, 1020, 1025) traps among others.
A variety of baits can be used to lure chipmunks into cage traps, including nutmeats, pumpkin or sunflower seeds, raisins, prune slices, or common breakfast cereal grains. Place the trap along the pathways where chipmunks have been seen frequently. The trap should be securely placed so there is no movement of the trap prematurely 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 2 to 3 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.
Cage-traps can be purchased from local hardware stores, farm stores, department stores, animal damage control supply companies, and pest control companies, or they can be 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. Dispose of chipmunks in accordance with state regulations. If euthanization is required, use a carbon dioxide chamber. Remember to check state and local laws regarding the type of methods for euthanizing wildlife.
Common rat snap 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 cage traps, but hard baits should be tied to the trap trigger. Again, “prebait” snap traps by not setting the trap until the animal has been conditioned to take the bait without disturbance for 2 to 3 days. 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. If snap traps are placed against structures, conceal them by leaning boards or plywood over them. Small amounts of bait can be placed at the openings as an attractant.
Resources: (online)
Chipmunks