My wife is fed up with squirrels attacking her garden. So we got a live trap to catch them and release them by her workplace. For bait we use peanut butter we put into half a walnut shell.
Spring has just started: we've only had squirrels routinely awake in the back yard for a week and a half or so. And we've already relocated four.
We have no idea if this effort will actually help, or if the back yard just becomes a "squirrel vaccuum" once emptied of resident squirrels, which will simply attract the nearest squirrel looking for a roomy unclaimed place.