Bizarre hole in foundation after wasp spraying
 

For the past few months I've had a nest of hornets or wasps behind my garage, in a gap under the back door sill. It was a big nest, judging by the activity around the entrance. I was unable to use my garage back door for fear of getting stung (I'm allergic).

Recently it was cold enough overnight to spray the nest. I sprayed over half a can of wasp/hornet killer. There was very little activity the rest of that day.

The next morning I was astounded to find a hole dug through an opening in a cement block near the nest. Dirt, stones, and nest remains were strewn around. Also a piece of cement block adjacent to the original hole had been broken off. See the attached photos. The gap in the top right is just below the door sill. That's where the hornets went in and out. The hole in the middle is where a drain pipe exits the garage. It had been completely underground and covered until the day after I sprayed. That broken piece of cement block below the sill had been attached.

I can't imagine that even thousands of frenzied wasps/hornets could have dug that hole. Yet here's never been a sign of any animal in that area – no tracks, no droppings, nothing ever spotted nearby. The opening in the cement block was big enough for a squirrel or chipmunk but I don't know if a raccoon or similar could have gotten in. Besides, what animal would reside directly alongside a hornet nest?

Can anyone hazard a reasonable guess about what happened here? Thanks.

You have more issues then just hornets with that foundation.
Really need to cut out some of those blacks and replace them.
Could be as simple as when you killed the hornets some critter saw them and just dig out the already cracked concrete block to get to more of them.

Good thought
 

That would explain the situation. I'd have thought nothing would eat hornets because it would be toxic to ingest the venom, but perhaps it's neutralized in their digestive system. Although it can't be good for anything to consume the residue from the stuff I sprayed.

The rest of the foundation seems fine. The only cracking/deterioration is around the door sill and drain hole, which is all you see in the photos.

Thanks for the reply!

Lots of critters will eat dead hornets, skunks especially love them:yes:

Even my dog was eating some yesterday. I'm up on a ladder spraying them and as fast as they hit the ground still moving around my dog was trying to eat them. ( yes I stopped her from eating them)
Could have been skunks, Possums, rats ECT.

Dogs will eat anything:laughing: