Client and I are baffled on what's causing these stains.

[First-light]

I used a bee trap this year and it worked great. Spayed the eves with a citrus solution and hung fake wasps nests. Had two new holes last week compared to over 20 last year. 

[knehrke]

On 6/25/2021 at 10:06 AM, mowin said:

If the holes are on the inside, how is the stain getting on the outside.   

You don't poop where you eat, right? They're very similar to the stains I see where wasps are crawling in and out under myi porch eaves.

[knehrke]

FYI, they'll come back to the same spot year after year. We have a "The Nehrke's" wooden sign hanging on the front porch...they bore a hole straight into it, the larvae hatch, they fall onto the cement, the dogs eat them...every year the same thing. One single hole. But the inside is riddled. Kinda crazy how they manage to keep returning - I guess carpenter bees can live for three years, and families can live together. So I guess the dogs must not get all of the larvae lol.