Animal burrow at house foundation

Asked September 2, 2019, 2:22 PM EDT

Dear expert: I have two animal borrow openings at the foundation of my house. The open entrances appear a semi-circle of excavated dirt, and slant into the ground. Perhaps a groundhog or gopher has made these holes. One of the holes is a repeat: I put a rag soaked in concentrated ammonia down the hole many months ago, and then filled the space with dry concrete mix and compost. The hole did not reappear for several months, but now it is back in the same spot, and with a companion hole about eight feet away. Question: What sort of animal lives there, and what should I do to discourage it from undermining my house? Thank you in advance for your response, Louis Finkelman ,

Oakland County Michigan

3 Responses

Would it be Possible for you to attach a couple photos?

Dear Prof. Badgley,
Have I succeeded in sending the photo to you?
I tried to attach it to this message, and I tried to send it to your MSU email address.
Perhaps I made a data entry mistake.
I will try again.
Best wishes,
Louis

Hello Louis,

Yes, this is most likely a groundhog, aka woodchuck. Sometimes skunks or opossums take over burrows made by one another, too. You will have to observe scat left in the area, or use a motion sensor camera with a light at night, to try and see which one. Although if it is a skunk the smell will tip you off.

Use a live trapping service to legally trap and remove the inhabitants. Michigan DNR licenses these folks to release the critters in certain areas. ( we aren’t permitted to recommend retailers- search your internet for animal control service or look at DNR link below)

Once the critters are gone, new ones can be excluded by installing hardware cloth bent into an “L” shape and fastened to the lower edge of the building. The lower part of the L is pointed outward from the building and buried at least 6, better 12 inches deep in the soil.

Fastened firmly with screws, this barrier will last many years. This works for akunks, opossums and groundhogs. Fall is a n active time for these creatures to get ready for winter, so the sooner you complete this, the less likely another will make another burrow. ( on a personal note, I did this for my house 28 years ago and haven’t had a problem since.)

Here are some references for you

https://www.massaudubon.org/learn/nature-wildlife/mammals/skunks/situations-solutions

https://naturalresources.extension.iastate.edu/wildlife/diagnosing-holes-yard

https://www.michigan.gov/dnr/0,4570,7-350-79136_79608_83071-137162--,00.html

Thank you for using our service.