Finding out that not much works for voles. Trying a product called Volex but not holding my breath. Tracking powders look promising provided they walk through it and groom but powders are hard to come by. Thinking about getting a car battery, putting two rods in the ground and picking them off with a pellet gun. I know they have rodent systems that puts propane and oxygen in the hole, ignites and instantly kills but can't find anyone in my area that does that. Not sure I want to go that route either since it's a neighborhood.