Here in mid-michigan woodchucks do such damage. Besides decimating gardens, they do costly damage to structures with their burrowing.

They are usually too clever for Havahart traps, but if you were to try them, apples and other pome fruits are the best bait. Also there are restrictions on where the animals can be released. My neighbor hired an exterminator, who charged $200 for thee visits- no guarantee. (They did get one.) When the real estate is to their liking, more tend to move in though.

They are diurnal, and can be asphyxiated in their dens at night. Your cooperative extension give you the details. One problem is the burrows have two or more opening which have to be covered simultaneously. Often one of the holes is on a neighbor's property! Probably you can't use this tactic under your house.

This past summer I had the best luck with a campaign of harassment. When I find a new pile of dirt, I put litter box gleanings down the hole, then backfill with the dirt and pile boards and rocks on top. This requires constant vigilance, but I'm retired and am out in the garden anyway. When I see a woodchuck through the window, I run outside and scare it off. (I guess I'm my own guard dog.) One day I saw one munching on my snow peas, and chased her right into the netting.

A fence at least 4' tall and 18" underground has been suggested, but again, they are clever.

I'd like to be zen about this. Fretting over wildlife is not good for the blood pressure. I hope you don't have woodchucks.

-Judy

In my neighborhood in California there are moles and gophers. I would think that such rodents would not be interested in what's under my sidewalk and foundation. We also have gray squirrels, racoons, and once I saw a possum in the back yard at night--big as a cat.
The plan is to board up the small cavity at the bottom of the foundation under the house, make a hole in the cement gutter outside the house, and pour in cement to fill the cavity.

Thanks Judy for your comments. My boroughing pests remain a mystery.

Jerry

filling the hole is probably not going to dissuade the critter ... especially if they already have made a home there ...

they are digging machines.. thinking nothing about moving over a few feet.. and digging faster than you can fill it in ...

i dont know about the cement part ... might be a future nightmare when a different project comes along ...

ken

I'd say gopher also. But it's just a guess, a California guess. And don't be surprised what they may be going after. They'll dig anywhere! I've had them dig in my dead front lawn only to get stopped by massive tree roots. Sounds like a massive mound for a gopher though.

Got a pic?

Kevin