One day I saw a squirrel poking it`s head out of the side of my house. I looked up Phillip's Pest Control  and had them come over. They quickly climbed up my steep third storey roof and found out where they were getting in and out. They also looked around for other openings and quickly found a second one. So they one of the entrances up sealed them up and put in a one way exit cage on the main entrance. The next day, I didn`t hear the squirrels any more. I haven`t heard a skitter or scratch since.