Has anybody ever used it for voles?

It looks like it's registered for use against them, but I've never heard of it.

Try ZP-AG by Bell labs.
pick65

Tracking powders and inhalation of the dust particulate of ZP is some nasty material so be careful in its use. You need to keep it relatively dry to be real effective in its use as a tracking powder. It is best used in an enclosed controlled area. They make pellets and baits with ZP actives but it has a foul odor in baits that I have used. I never had a lot of acceptance with a few baits I tested with ZP and used over the years.

If you are a certified applicator in most states you must be to use it, there are better and safer alternatives in vole control. There are a couple of baits labeled for vole use that are more acceptable and safer to handle than ZP active baits or tracking powder.

What have you found that's more effective?

I have my structural and as soon as the paperwork is processed ornamental and horticultural.

You need to see what is registered for your state. In Ohio, we are limited with our choices for voles with ZP in Rolled Oats most likely being the most common.

Mr. Jameson is right on the money. I have never seen any bait avoided like the rodents here avoid zinc phosphide. I would have better

luck over-feeding our voles and hoping they die of a heart attack.