I use Fox Urine to rid my yard of squrrils. A little expensive, but think about the guy that makes a living collecting that stuff. Also seems to work well with field mice, chipmunks {rats with racing stripes} and other assorted varmits. This saves me from getting out my Mitt Romney varmit gun.
I also have a cheap way of getting rid of chipmunks only. It’s called the Bucket of Death, works everytime. Chow Jim