I've got squirrels in my attic

I'd seen the buggers coming around the house a little more the past couple of weeks. The old owner said he used to trap and "dispose" of them quite often to keep them out of the house, and out of the pear tree. He said he thought the tree didn't bear fruit at first, then realized the squirrels were eating every bit before they could ripen.
Last night, I heard the scratching in the attic. My plan is to use a live trap outside the house, and put a peanut butter baited rat trap in the attic. I will begin my quest to find their entry point also.
Any suggestions to remedy this annoyance?

I've been told I have bats in my belfry. If you come up with a really good method of mammal disposal, please advise.