My husband, and I live on 20 acres 11 miles outside of Bend OR. Voles have destroyed our lawn my husband has flooded the holes w/water, he's loosened them, he even started shooting them with his 410 shot gun. I started a butterfly/hummingbird garden last year, and everyday I'd go out to work, and they had feasted the night before. I bought just regular Castor Oil (consumable by humans) I put it into a sprayer, diluted it just enough so it wouldn't clog, and went out and sprayed the plants in my garden. It's only been a couple of days, and so far I haven't seen any. I even poured pure Castor Oil around the base of the plants. My husband is going to spray out lawn, and I suggested that we pour undiluted Castor Oil into the holes. We don't have a lot of lawn around our house, just enough to enjoy. I'll keep you posted. I'm going to be starting my veggie garden soon, and I'm goings to use the same process. I hope this helped !

I'm shocked to see some of the comments here on castor seeds being poisonous. Growing up in the Caribbean we picked the pods and laid it out to dry just to hear it pop and see the seeds fly out. Now that I'm older and trying to adopt a much healthier lifestyle I have been using oils such as castor oil, rosemary oil to name a few for my hair. It does wonders for my hair and scalp, no itching no dandruff and promotes great hair growth as it helps with circulation . Picked some pods just this morning. Rastafarians have been using it for centuries in their hair and to oil their bodies after a shower. I also know that fresh pure castor oil can be ingested to purge and it works immediately too. Someone mentioned on this forum it's cheap. Let me tell you good pure castor oil is not cheap you can easily pay a good US$50.00 or more for a liter. I know that pharmaceutical grade is available as well and seem to be a little more affordable but I don't use it.

Does anyone have any more care instructions for these guys? I purchased one recently but I can't find anything online about it. I have noticed that it dries out quickly and, when dry, loses some of its metallic sheen... but that's about it. I wonder how big they get?

I don't know of any scientific studies that support or debunk this idea but I can give you my experience with moles. I had a serious problem with moles, tunnels everywhere in the lawn and flower beds. I sprayed the castor oil mole repellant as directed (note, the directions are VERY important since it must get to the level the moles are traveling through) and within a couple of weeks I didn't have any moles left. Now I can't say for sure it was the castor oil but if not, then the timing was certainly good! It doesn't harm the critters but is supposed to be unpleasant enough that they will go elsewhere to forage for food. Good luck. I would say it's worth a try. Sandy