Traps work.

These windmills, sonic vibrators, juicy fruit gum, and hundreds of other things meant to control moles so not work. Even the traps will not keep moles from your yard, although with luck you might kill some. I know people that annually kill several moles and have for years and stil lhave moles. As long as there is a food source, earthworms, the moles will be there.
One deterent that does work is to mix 1 pint of Castor Oil in a 1 quart hose end sprayer, filling the sprayer with water after adding the Castor Oil, and spraying that over 2,500 square feet and then watering it in well. The mixes sold in stores will not be effective because they contain less than 1 pint of Castor Oil and tell you to cover much more territory and that simply is not effective.

I find it hard to believe that the vibrations created by a small windmill would be enough to cover any significant length of area. I have had very good luck repelling moles from my lawn with castor oil, though I would recommend first buying the product sold in the stores with the sprayer attachment, using it at about 3x the suggested rate (b/c as kimmsr said, they tell you it covers more than it should), then when it's empty, refill it as your castor oil sprayer, as the oil is very difficult to wash out of your regular hose-end sprayer. I repeat every 3-4 weeks or so to keep a constant defense.

My dad built & used mole-windmills for years with great success.
He'd take round Clorox bottles and using a razorknife or penknife would cut 6 or 8 three-sided "flaps" on the sides of the bottle. Cuts were about 1" at top & bottom, and 6-7" lengthwise. Once the 3 cuts are made, you could fold-out each "flap" to catch the wind.
Several 2-sided "V-shaped" cuts were made on bottom of the bottle also, about 1" in from the edges, and the point-end of each "V" was pulled/bent out in order to help catch the wind (NOTE: make sure the "V"s are pointed in the same direction as your side-flaps to catch the wind).
Then make a small round hole in the center of the bottle bottom (you can drill, or heat up something & melt the hole). Invert the bottle and slide it down over a 3-foot dowel with one end rounded (like the top of a broomstick) and attach the bottle to the round-end of the dowel using a smooth-sided small nail. Don't hammer it home, as the nail is there only to keep the bottle centered on the rounded dowel; it should spin freely.
The dowel is then driven into the ground about 8-12", and (if you've done it right) the bottle will spin round-and-round in the slightest of breezes.
There should be plenty of "play" between the dowel and the opening of the bottle, as the desired vibrations are made as the bottle spins 'round in the wind and the (cape-end) opening rattles back-and-forth against the dowel. The vibrations which are transferred into the ground via the dowel.
I think he placed windmills about 40 or 50 feet apart, and (even though having a bunch of clorox-bottle spinners in your yard makes the place look sort of red-necked) this remedy is cheap, humane, non-toxic, and by recycling this stuff, makes you "green".

Clorox was the bottle of choice because the top opening (cap-end) was centered, and because it had a flat bottom. Two-liter soda bottles or detergent bottles won't work, they don't spin properly.

I've made these myself, and you'll want several bottles since getting those "flaps" cut straight and even is more difficult than you might think.

Whether moles think "Something is up there", or maybe they just don't like the vibrations, I don't know... But I do know that ol' Dad kept his lawns mole-free for years using these things.

Castor oil does not work, no matter what these people say. I have tried everything to get rid of our moles. I usually either kill or remove atleast 5-10 moles from the property a season, and I have never got rid of all of them. We even have 4-5 snakes on property that I know kills at least 1 or 2 a season.

I have planted every variety of castor plant, as it is said "moles hate the roots and the chemical they put off"--BS--my moles, spite me I am sure, ran circles around my castor plants, and the castor oil, they can care less. There fur is super slick, they smell the oil, and they just dig deeper till no oil, or in an area with no oil.

Good luck guys, only way to get rid of these things is to exterminate them by hand or trap. Make sure you get them in the spring, because that is when they breed!!!!!

You will never get rid of moles, and you would really not want to because if these wee critters are removed from the face of the earth that means we are in real trouble. Moles are a fact of life and as long as a food source is there, earthworms primarily, the moles will be searching for them. You may well kill one and as soon as you do another will move in to take the place of the one you killed and that is why people will trap 4 or 5 or 45 in one year.
Castor oil, according to the turf grass people at Michigan State Universtiy, flavors the moles food source, the earthworms and grubs, so the mole does not like the flavor and they leave to find a better tasting food source.