The weasel box with the yellow pan rat trap works great on chipmunks and the little red/pine squirrels.

This is what I have had the most success with also. I smear peanut butter on the pan and sprinkle sunflower seeds into it. I have also used the "old maids" from popping popcorn with equally good results. A couple years ago, I caught 26 chipmunks around the outside of my garage with this setup and also caught many more mice than that at the same time.
Being in an enclosed box also prevents non-targets like birds from being caught.

Yup, I killed several wrens with the open traps. Even got a few in my small havahart. They really get around in some sneaky places.
I like wrens. Hated smacking a few.

can you point to a video on how to build that? I want to see how to setup a reliable DIY trap.
I built one cage trap but the animal was escaping somehow. I did not have a latching mechanism, so if it was smart enough to lift the door then that was how it escaped.

I always figured that you had other uses for the "Old Maid's".

Wrap string around the trigger and let the peanut butter soak into the string. Teeth + string = DEAD

TrapperKent