Every spring and summer, I get a yellowish type stain on my window located near my porch. I have a wood house and I attract carpenter bees. Above the windows, there are roof vents. It is possible that the bees feces are the culprit? I can send you a picture if you like. Also, what can I spray in these vents to stop this from happening?
It would be helpful if you could send a photo. We get lots of questions on this problem and a good image could prove helpful at some time in the future.
Based on the time of year (spring), it’s quite common for people to see yellow stains on siding, windows and other areas of the home where carpenter bees are active. In most cases the stains are in fact carpenter bee feces. Pollen is their main food source and if nest access holes are close to the siding, many times their feces will fall directly onto some part of the house. The result is a yellow “streak” which can have some other colors mixed in. It sounds like this is what you’re seeing.
If you review our online CARPENTER BEE CONTROL article, you’ll learn the best way to treat nests is with some DRIONE DUST. If you aren’t able to see their nests, I suggest you take a little time to watch the area where you see the stains. If you sit long enough from mid morning to mid day, chances are high you’ll note some bees coming and going. If you see them you’ll no doubt learn their access points. Many times they’ll crawl through small cracks in the siding or around attic and soffit vents so I’m sure their nest is close to where you think it might be. Once identified, dust these passageways and you’ll stop that nest for sure. This treatment will work even if you cannot treat the nests directly.
To stop future nests from forming spray these same areas with the CYPERMETHRIN discussed in our article. It’s highly repellent to bees and wasps and will keep them off treated surfaces. They’ll immediately detect it’s presence and move away from your home. You may need to do a few treatments this spring but in general one or two is all that’s needed for the season.
Here are direct links to the information and products mentioned above:
Bee Article: www.carpenterbees.com
Crusader Duster: www.bugspraycart.com/equipment/dusters/crusader
Give us a call if you still have questions.