Tennis ball to keep them occupied?
Heck, when we first moved into this house, there was the most god-awful looking plastic garden statue of a squirrel. Think dollar store quality, then pick the ugliest one you've ever seen. Our golden went nuts trying to get to that thing; it was pretty amusing. He'd go outside and stand at the end of his leash barking at that thing forever. One day, he got loose and got to it; the statue is no more.
Oh, he was also a better mouser than our cat; he caught plenty of mice and a couple chipmonks. But, there's nothing worse (or funnier, since nothing was broken) than a live chipmunk escaping in your living room, running behind furniture, and a 100+ lb dog chasing after it. Couches and chairs were flipped over.