what is this weird hole?

Asked August 27, 2018, 7:52 PM EDT

Hello, I noticed this today, wasn't there a month ago, very low traffic area, I can't imagine what made such a perfect circular hole, it wasn't from anything I was doing, It's about 4 inches in diameter, and you can kind of see, at the top of the picture, that there is a cavity, so maybe it's some kind of animal burrow? Could it be a yellow jacket nest? There have been a lot of them around this summer, but there was not activity when I saw it about noon today. Thanks for your help, Nanette

Multnomah County Oregon horticulture

5 Responses

The source of mystery holes in the garden isn't always easy to resolve.

I don't think it's a yellow jacket nest because they're normally active at noon.

One method to determine if a mammal dug the hole is to spread a thin coat of flour around the hole at dusk and, then, inspect the ground in the morning for footprints. If any are seen, we can match them with known examples.

Or, perhaps the hole is currently inactive. To test that theory, cover the hole with soil, then check in a day or two to see if it was cleared away. If it was, use the flour track method suggested above.

Thanks, yes it is weird. I'll try the flour thing, but the surface around the hole is gravel, so don't anticipate getting much in the way of a distinguishing track. Will probably just fill it in and see what happens. It's curious how almost perfectly round it is, and how there is no pile of material surrounding it, as it seems like there would be if some critter dug it out. At least it's not yellow jackets.

Thanks again,

Well, I'm also curious to know the answer. Let me know if you find something.

Hi, sorry for the delay. I did fill in the hole several days ago, and it has not re-appeared. So who knows?
Thanks for your help with this,

Thank you for the update. Perhaps something began to dig the hole but then abandoned the effort for some reason. We'll probably never know.