I went to my local Agway in massachusetts and asked about killing voles. The person there had me buy Agway mole control. I said will it get rid of voles? She said yes. I had a long tunnel through my flower bed and sprinkled it on this fall no more vole or mole problems showing. Last year I had to replace lots of flowers because of voles. My neighbor had lots of voles in his beds and the problem stopped very quickly after using this product. It doesn't say what's in it but it seems to work for the season.