Okay, here is the good stuff to kill those voles. I have been using it for 1 month and has not harmed my grass at all. Available at Menards Homewood, the Matteson store is always out of stock of the product.
TOMCAT Mole & Gopher Repellent. SKU 2095205 Item 348206. $15.00 treats 1000ft. effectively repels moles, gophers, voles, armadillos and other burrowing pests, Ground penetrating technology GFT improves castor oils ability to mix with water and sink deep into the soil.
Does it work?