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

[mowin]

3 yrs in a row, these stains appear every spring.  We can't figure it out.  I clean them off, and they don't reappear until the next spring. It's the only two spots on the entire house.  We're stumped. 

 

[Cabin Fever]

At first look, I thought bat guano. But, I don't see any holes above that for them to be coming and going through?

[mowin]

6 minutes ago, Cabin Fever said:

At first look, I thought bat guano. But, I don't see any holes above that for them to be coming and going through?

Same thoughts. But on further inspection on a ladder,  I couldn't find anyplace for one to hide. 

[KMurph332]

Carpenter bees

[mlammerhirt]

Spider crap??

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[Swamp_bucks]

I have seen bats just hanging on the side of houses and trees they don't always end up in an enclosed area.  So it could be that but I don't know.  It is weird it's only 2 spots 3 yrs in a row.

[greensider]

Put a camera there 

[mowin]

2 hours ago, KMurph332 said:

Carpenter bees

Nope.  They always punch a prefect 1/2" hole and leave wood shavings, not a stain. No evidence of a hole or shavings. 

[mowin]

1 hour ago, greensider said:

Put a camera there 

Thought of that,  but someone has to have experienced this same shit..... or stuff???

[Moho81]

I’m pretty sure I’ve seen a stain just like that on a house before but I’m of no help because I don’t know what it is either.


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[ncountry]

Maybe a leak in the old rusted gutters ?

Looks like I can see a hole or drip? Above the one stain.

[mowin]

7 hours ago, ncountry said:

Maybe a leak in the old rusted gutters ?

Looks like I can see a hole or drip? Above the one stain.

There copper gutters. It does look like there's a hole in the gutter, but there isn't. There no seam there either.  

[chads]

100% wood boring bee's   Spray the hole with SEVEN

[Arcade Hunter]

I vote for spider poop

[Moho81]

59 minutes ago, chads said:

100% wood boring bee's   Spray the hole with SEVEN

Now I remember where I saw the stain before! 

On my shed right where the wood boring bees drilled holes in the trim. Now I wish I was home to take a picture because I bet it's almost identical to @mowin stain picture.

[knehrke]

That's what we see when the boring bees show up. The holes may be on the inside, invisible on inspection.

[skully]

Its carpenter bees....  100 percent

[LET EM GROW]

My first guess was carpenter bees but i dont see any holes they bored. and shavings should fall to the ground. 

If its a stain, My 2nd thought would be some sort of larva hatching or breeding grounds or some sort for insects. That side of the house probably stays out of the direct sun more than others? 

[mowin]

3 hours ago, chads said:

100% wood boring bee's   Spray the hole with SEVEN

There is no hole anywhere near there or any sawdust on the ground. 

I've got them all over my shop, and have never seen anything like that, but my shop isn't white. 

Edited June 25, 2021 by mowin

[mowin]

2 hours ago, knehrke said:

That's what we see when the boring bees show up. The holes may be on the inside, invisible on inspection.

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

Edited June 25, 2021 by mowin

[mowin]

Well, I just did a Google search for carpenter bee poop stains.  

And everyone that guessed carpenter bees is correct.  

Is so odd because there isn't a hole anywhere along that entire side of the house, and I'm there every week mowing his lawn and never seen any sawdust either.   

[Enigma]

Powder post beetles perhaps. My parents had them in a beam in there garage. Similar staining of the painted wood and no large bore holes like carpenter bees. Very fine and very small amounts of sawdust expelled at the damage site. 

You can drill holes in the wood, inject insecticide, plug holes, fill and repaint. Call a pest management company to confirm. 

[skully]

Its carpenter bees...  100 percent------- There does not have to bee holes for them to stain the wood............

[mowin]

5 hours ago, skully said:

Its carpenter bees...  100 percent------- There does not have to bee holes for them to stain the wood............

They definitely shit alot, lol

[blackradio]

Definitely carpenter bees. They come out in full force in May. These work really well. 

https://bestbeebrothers.com/products/best-carpenter-bee-trap?gclid=Cj0KCQjw_dWGBhDAARIsAMcYuJwr4m_chaTDVQAuGXZ4sg0obsK1nM7scyiL32aibS6qRWsJGsRkH9kaAubYEALw_wcB