I get the "hate the squirrel" bit, but unfortunately nature abhors a vacuum, and if you get rid of the current population more will move in. We get red squirrels…...the worst for invading your house.......and lately the blacks and greys seem to be showing up as well. Raccoons are more worrisome, and I would not want my dog to get into a scrap with one of those, although my friend's JRT has dispatched quite a few! We also periodically get rabbits, but it seems to be a bad year for them. Haven't seen many. Skunks are the critters I fear most. Quite unpleasant to deal with the Basenji vs skunk aftermath. Especially as Basenjis are indoor dogs. When my Border Collie made that mistake, he was the only one who had to live with it!
My Perry used to climb his breeder's six foot chain link fence to go after squirrels, until she discovered that a piece of PVC pipe attached at the top effectively deterred him. He still climbed, but couldn't get over it. Since he has been an off leash dog here, he has been able to chase squirrels and has discovered that they, like the crows, do not "play fair". I always make sure the squirrel has a good head start, however. It does tend to send them away at least until the next day.....