Iron pyrite will acidify your soil. It's the main cause of acid mine drainage. I doubt it will have much impact on voles.

Only two things have worked to keep voles under control in my yard. Snakes and hawks. Even the two Rat Terriers can't do as much as the snakes do. I wish there was a rodent-eating snake that stayed active all year.

Well, I'm gonna do something with this pail of pyrite. Just thought I'd ask.

Maybe you could incorporate it into some hypertufa and make some planters.

Now that's an intriquing idea. Hadn't thought of using the pyrite as decoration since it's such small pieces. Hmmm... you've got my creative streak thinking. Thanks !

Has anyone tried placing mounds of Chiclets gum out around your lawn? I recently heard a conversation on WBT talk radio about this technique.

sounds like a hoax to me. Why would gum be dangerous to a rodent and not to a human - they're both mammals with similar digestive systems.

I think my mistake was in even bringing up the topic of voles.