Anybody tried straight castor oil applications to keep the voles away? I take care of a 3 acre apartment that had VERY bad vole damage over last winter and last spring. They are mostly gone - I still see a couple when I mow, but at least its not the 50+ I was seeing each week this spring. This apartment borders an overgrown/unkept lot so the voles will be back this winter. After looking at all the vole repellants online, it seems castor oil is the active ingrediant. I have a tow behind sprayer and was thinking of putting down a couple applications of castor oil(diluted with water) this fall to keep them away this winter. Has anyone done this before, at what application rate, and how were your results? Of course I will check with my state Ag office to make sure I dont need a special license. But I dont think I will because its not a chemical.