Having a dog deters most of the wildlife from my yard. He wouldn't know what to do with one if he came face to face, but somehow just his scent keeps the racoons, 'possums, and woodchucks out of the yard, even tho my neighbors have some problems. Doesn't deter the squirrels, tho - they must have gotten to know him. THEY sit on the picnic table (where else) to have their snacks.

However, it leads to other problems - not much but quack grass and dandelions stand up to the wear and tear on the yard.