I've had a terrible time with voles here in NW PA. All the tulips, nearly all the lilies, Siberian Iris, gone. A young Apple girdled. Potatoes gnawed. I won't poison because lots of critters eat them here. YouTube has some excellent how-to videos on how to use mousetraps. I tried the "bait w/peanut butter and poke plastic traps down hole" technique with some success. Am now cutting the narrow side from short sections of rain gutter. Placed over the opening of a tunnel, unbaited traps facing both directions. Mousetraps [classic Victors] drilled so they can be spiked to the sod with a large nail so they don't waste kinetic energy flipping. I hope they work.