Glad you asked...
One of the easiest ways to trap a chipmunk is to purchase a Have-A-Heart trap. All you need to do is place a small amount of food inside and wait for the chipmunk to get caught inside the trap.
Then again, this answer might help you...
You can make a chipmunk trap out of metal or wood, and to make it effective, you need to have some kind of bait, such as oats or nuts, to lure it in.

