Here's a little trick.
Go to the pet store and buy a bunch of Rabbit or Gerbil treats. You know the kind that has a mix of tasty little morsels likes nuts, corn kernels, dried fruits and veggies. Not that pellet crap. Wild animals don't like that ****.
Then go to the hardware store and buy some grade A rat poison.
Mix the tasty little treats with the poison then put nice little piles of the mixture just outside of their holes.
They'll see the treats and think "Hey this Dimitri guy is a pretty swell fella" and then they proceed to eat it all up poison and all.
You'll be picking up little chipmunk carcasses in no time.