If you are positive ID that it's actually voles and not something else... and positive they are actually coming in from another yard and not already established in your yard...

You can use repellents that are sold in many big box stores meant to repel critters like voles and rabbits. There are likely going to be little holes in the ground where they have entrance/exit points in your yard- make sure you use the repellent extra in those holes.

Some folks speak of using stuff like mothballs or used kitty litter in tunnel entrances to deter too, but I can't vouch for if those work or not. Predator urine is purported to help, but is often expensive, stinky, and needs regular applications.

Clean as much debris like woodpiles, mulch, weeds, and dense ground covers out as you can. Keep your grass consistently short to help deter their wanting to hide/eat in taller grass.

If they are coming under a fence, you can try either sinking hardware cloth a few inches deep or a fine gravel trench a few inches wide and deep along the entire fence line- voles aren't fond of trying to tunnel through hardware cloth or a bunch of gravel.

If you don't mind death, you can set up traps to kill them. There's a couple different kinds of traps you can use, some more or less humane than others.

Do NOT use poison- often enough, predator animals end up eating poisoned critters, and get poisoned too. Do NOT trap and release them into another area- it often does not work, and the voles die anyway- and it's also rather rude to release that kind of critter into another area to do damage there.

Yes I do have voles as I have seen them poke their heads under the fence and then slowly come into my yard. They live under my neighbours deck and they are trying to get rid of them. I like the idea of using gravel or hardware cloth. Can you describe the hardware cloth I should use as I don’t know about that please? Also, I do have a patch of grass between my driveway and the neighbour that has deep holes and I see them there too. I am trying to plug them up with soil even though they are super deep. Perhaps I should place something other than soil there? Is there perhaps I mesh I could use or something else so they stay out of the holes? Thank you so much - you are very helpful.

Hardware cloth is fine mesh metal fencing, used for all sorts of stuff. You can get it from your local big box and often smaller hardware stores. Use 1/4 inch or smaller size.

Plant it 2-4 inches deep, and it should come up 10-12 inches above ground.

Anywhere you got those little 3 inch holes, drop in some of the repellent. Then close up the opening. Don't bother trying to put mesh in- that will just mess up your lawn care later with a bunch of little bits of metal mesh around on the ground.

A lot of places sell castor oil granules, but it's a lot cheaper just to buy the castor oil yourself (Soaper's Choice online or any place the sells castor oil for soap makers).

Here's an internal link: https://www.houzz.com/discussions/5374471/best-castor-oil-for-repelling-voles

Please note that the voles chewing on castor plants were not exposing themselves to castor oil. :-)

I tend to mix the castor with some soap as well for penetrance.

You can't easily plug with soil because voles are born diggers. They'll simply dig right back through any filling in you do, or just shrug (figuratively speaking) and go around it. As far as landscape cloth, though, you can get that at Home Depot or any other good big box store in the garden department!

Thank you for describing the hardware cloth. Are you suggesting caster oil to place in holes as well as under my fence? Thanks.

You can, and it would definitely keep them from using those holes. But if you spray the area (as described in the thread) they won't feed there or use the area at all.

Add some soap and it works for moles, too, if somewhat less reliably for them. BTDT, saved my dahlias using it. It makes the stuff they're eating (grubs, earthworms, insects) taste awful and smell awful to them (castor, to us, is pretty scentless) and has...unfortunate dietary side effects to mammals when consumed (it's sold as a minor laxative for babies and children). Voles and moles will decamp and go elsewhere if they can.

Unfortunately, if they're extensively inhabiting your neighbors' properties, they may not go far.

I always have around a gallon or so on-hand for making soap, so supplies here are easy and it keeps for five or so years. For voles, use 1 pint per thousand square feet. The recipe differs for moles. In either case, I'd be inclined to add 1 oz of soap to the hose-end sprayer for penetrance.

Thanks everyone so much for all of your help. I appreciate your patience in answering my questions. Take care.

This article focuses on prevention. https://metromolecontrol.com/vole/how-to-prevent-voles/

If you have voles you can either trap them with regular mousetraps baited with peanut butter and birdseed. Many people will drill a hole through the center of the trap and drive the trap into the ground with a nail. A vole is a bit larger than a mouse and this makes the trap more stable when it snaps. The best advice is to keep the lawn cut short and clean up any debris.