Mark came to our house on November 22nd, and installed a one-way door where I could see the squirrels had chewed right through our aluminum soffit. That seemed to slow them down for a while, but two weeks later I was still hearing squirrels in the attic. Mark came back and found two other locations where the squirrels had tried to get in, and had gotten in one of them. He blocked both of these locations, and although they subsequently tried to get in one of them later, they didn't succeed.
I was extremely satisfied with the service provided by go pest control, and would highly recommend them to anyone.