...this stuff works great..
http://www.enasco.com/product/C27189N
I took a large coffee can and cut a hole in the top big enough for a squirrel,so cats and dogs couldn't get in...used duct tape to secure the top even more, then just dropped a 1" sized piece in the can. I have a large garden..they ate every single one of my broccoli, brussel sprout, and cauliflower plants...I did try all of the "nicer" fixes...but this stuff works!!! When they started on my squash and tomatoes..they had to go....
Anyway...it takes about 4 days...so put it out in 1" chunks till there isn't any more activity, then just monitor after that.
I tried everything before this, killing them was my last choice, but they were wiping me out.