I have an infestation of voles I have contacted pest control and yard maintenance companies, none of whom deal with this, and one of whom suggested I contact you, said that they saw a lot of discussion on this topic by you. Can you advise on how to do with this? It is a fairly serious infestation. I have several places with holes 4 inches wide, in addition to the smaller holes. And the grass that has been planted is now dying in patches; I have been told it is because the voles are eating the roots. Is there any advice you have, any produce you know of, any procedure that will get rid of them? Once again, this isn't a minor problem.
Here is our information on voles:https://extension.umd.edu/hgic/voles
Please read through it and see if it matches what you are seeing.
Normally, repeated snap-trapping is a good way to control their numbers, and now through winter is the perfect time to do it.
While they will use holes that others make, 4 inches is big, and not likely caused by them. That could be a larger rodent. (and snakes would be your best friend.)
Many pest control companies do this type of work, so if you don't want to do the trapping/control yourself, do a search and find companies that do. They often use enclosed bait stations.
We are happy to look at photos you may have of the damage and signs you are seeing, and give you our thoughts. Photos can be attached directly to this reply, by clicking the 'choose file' button below.