<<<< These two 25 lb. Beasts...They would be Sam and Dave and they are Boston Terriers. The squirrels try and steer clear of my yard, they don't stand a chance. My boys are pretty damn fast and with two of them on a squirrels butt there is no way out. They catch 5-6 a year!
Of course some dogs have been specifically bred to be "ratters" but my experience is some dogs just have a high prey drive and are good hunters (and fast).
One of the five Rotties I had could stack e'm up like cordwood ( if I let het). She would actually be crying as she was chasing them. Loved the hunt.
mountain fiest or cur. my dad has a mix of both and its a small breed (20-25lbs). loveable, smart one minute and kill a coon the next. its a tree dog. my dads trees coon and squirrel. neighbors has a ton of cats with front and back porches. it got loose and effectively kept the cats 'porched' on both sides.