I haven't been in my storage shed since spring when I put away the snowblower and brought out the patio and garden stuff. Anyway, yesterday I opened the door and that ripped open the hive they built over this summer. I only got stung twice and I was happy. Believe me, they were not happy. Got out there after dark last night and sprayed the ones that were left. I did read mud wasps never use the same hive twice.