What do you do after catching several moles in a yard, to keep them from returning?

I read on the other thread where someone puts the mole carcass back in the tunnel with some success.

What do most of you do for prevention?

Since we have not a single mole in this part of the country I'm thinking that I should be selling some of our mole-free soil to you guys to use as a preventative.

I would water your lawn a lot

The only sure fire method would be to pave it. You could exclude the yard I guess if you put a barrier 18-24 inches or deeper in the ground around the whole perimeter of the yard may work. The cost would be really high though, they could trap them for years on what I would charge for that. Watering calls them in so would not do that.

Most products that supposedly prevent moles the active ingredient is castor oil most that is all it is is castor oil. I have never used it. Moles are not a big part of the food chain so they don't reproduce in large quanities and they are not social which is what makes trapping so effective on them.They only come together for (i'm an idiot);-). If you are in an area that has a lot of insects and or worms you probably will get a call back because moles hate digging and the neighboring mole will take over the deceased moles efforts.
I tell people that. To make it more bearable that solving the problem will take some time and management but if they stick with me they will eventually have no or few moles I do an annual service call and then a per mole price during that year. 125.00 and 60.00 each is I know the next question. If you spray for grubs and a mole is barely making a living may move. Or if they would want to do some extreme chemical treatment to eliminate worms which make up 80% 0f the moles diet he would have to leave.
Pesky I agree with RF dont water unless you intend to try drowning the $$#%$#&ers. Som e times especially if it is fairly dry I will set my traps and water the area where my traps are. He knows that the water is going to attract a lot of food and he will come crawling. The only thing that may bring him faster would be (I'm an idiot who doesn't have manners#$#@*^)
Finally there are a couple of threads on here reference moles that have a lot of knowledge. That is where I got most of my info. I personally have never caught a mole but I'm pretty sure I could if someone would pay me.

Nothing. Moles are active year round. If the frost line is 3' down in the winter the moles will be digging 3.5' down. Moles will move up and down in the soil as it goes from wet to dry throught the seasons. If you apply castor oil, it may penetrate the soil a few inches and keep the moles just under the surface but it will not get rid of them. Poisons for worms and grubs work the same way. You may catch the moles in a customers yard but more will move in as the young of the year disperse. Once the resident moles are gone picking off the new ones is easy.

Good way to invite more back.