Killer Bees Destroy House

April 12, 2010 | By | Comments (13)

OK, that title is what we literati called “hyperbole,” but it did get your attention. And there’s another thing grabbing your attention right now if you walk outside near any wood — big, black bees hovering in the air like little helicopters. What are they? Whacked-out bumble bees who have been drinking at Starbucks?


Nope. They’re not bumble bees, but bees that look very similar — carpenter bees. Don’t be afraid for yourself — the males don’t have stingers and the females rarely sting. Be afraid for your wood siding, deck, or porch.

While both bees pollinate flowers, here are some importance differences between them that can help you differentiate them.

1. Carpenter bees nest in wood and can cause serious structural damage if there are enough of them (see photo below). They don’t eat wood like termites, though. Bumble bees nest in the ground.

2. While both bees are mild-mannered and rarely sting unless provoked, carpenter bees hardly ever sting because it’s the stingerless males you mostly see.

3. Carpenter bees have a light-yellowish band behind the head and a shiny black abdomen. Bumble bees have a whitish band and a dull black abdomen.

4. Bumble bees mainly concern themselves with flowers. Those hovering bees you see are male carpenter bees defending their territories against other carpenter bees. They’ll try to chase off anything that approaches the nest, including you, but it’s all a bluff, because they can’t sting.

So what’s the problem with carpenter bees? Here’s a hole one of them carved into my deck. It’s about 3/8-inches wide and almost perfectly round.


Big deal, you say? What if I told you the wood was pressure-treated pine that’s so hard it’s difficult to drive a nail into? This bee chewed through it like a brownie.

I thought a primary purpose of pressure-treated wood was to prevent insect damage. Unfortunately, the Feds decided to take out the arsenic that was part of the chemical treatment, saying it was a health hazard (yeah, mainly to termites and carpenter bees). My old deck stood for 10 years without one iota of insect damage. This new PT wood gets riddled right away. (Consider this when putting new PT wood into the ground.)

What can you do to protect wood against carpenter bees? One thing is paint it. For some reason, carpenter bees prefer unpainted weathered wood to painted wood. Second, if you are so inclined, spray the unpainted wood according to label directions in spring with an insecticide containing cyfluthrin, such as Bayer Advanced Carpenter Ant & Termite Killer (it kills carpenter bees too). Pay special attention to the under surfaces of decks, porches, and railings, as carpenter bees like entrances to their nests to be hidden. Also spray all old carpenter bees holes, as new bees will move in if you don’t.


  1. Steve Bender

    Carpenter bees do live in Australia. Check out this link:  GG

    June 27, 2011 at 1:41 pm
  2. Alana

    where are they found because i live in Australia and there was on eat pollen in my backyard it was defiantly that one.

    June 24, 2011 at 1:54 am
  3. Betty

    We had the carpenter bee problem along with woodpeckers coming along in search of the eggs. Double trouble. The woodpeckers knawed deep groove lines along our roof lines. Woody Woodpecker was cute, in the movies only.

    May 1, 2010 at 7:56 pm
  4. Grumpy Gardener (His Grace)

    One tell-tale sign people should look for is sawdust underneath anything that’s wood. As others have noticed, carpenter bees prefer to drill holes on the undersides of things, both for disguise and also to keep the rain out.

    April 22, 2010 at 8:14 am
  5. Jennifer

    This is the first spring we have had our new picnic table outside and these bees have been all over it. I never saw them land, though, and thought it was the stain we put on the table. I found 3 holes in the underside of my table this afternoon and was furious! The stain was a deterrent, at least, b/c we didn’t stain the underside of the boards and that’s where the holes were. Could put my pinky finger in it! Thanks for the advice and heads-up..although I guess it’s a hind-sight issue now! I’ll be getting the spray.

    April 21, 2010 at 4:33 pm
  6. Peggy Bayne

    I watched one drill a hole last summer. Thanks for the advice. I will be painting filling holes and painting this week.

    April 21, 2010 at 12:45 pm
  7. Grumpy Gardener (His Grace)

    If it were just a few holes, I’d agree. Problem is, sometimes the damage can be severe. I’ve seen cedar siding on houses totally riddled. Spraying the underside of my deck has worked. It’s kept the bees away.

    April 19, 2010 at 7:51 am
  8. UrsulaV

    In fairness, the lowly carpenter bee is an important pollinator. With honeybees suffering under colony collapse disorder, we may be coming on a time when we’re willing to sacrifice a few holes in the deck for getting our plants pollinated.

    April 18, 2010 at 10:45 am
  9. Jess

    Last summer I saw a bunch of these, looking like bumblebees on steroids. They never bothered me. I had no idea they were destructive!

    April 14, 2010 at 8:44 pm
  10. Jim Long

    They don’t seem to mind opaque stains, either. They go after every building on the place. I worry if I spray to kill them, I’ll also be killing the lizards, occasional bats and who knows what else. I guess it’s either that, or accept Swiss cheesy wood.

    April 14, 2010 at 12:42 am
  11. Jim Long

    They don’t seem to mind opaque stains, either. They go after every building on the place. I worry if I spray to kill them, I’ll also be killing the lizards, occasional bats and who knows what else. I guess it’s either that, or accept Swiss cheesy wood.

    April 14, 2010 at 12:42 am
  12. Jean

    They like the underneath part of the railings on my steps.I guess one day when I grab hold of the railing…there will be none! Only carpenter bee holes!

    April 13, 2010 at 11:16 am
  13. Vikki

    Thanks for addressing this issue Steve! The carpenter bees love the overhang of our shed and in the last two years have drilled at least 15 holes front and back. I’m off to get some of the Bayer Advanced stuff that you recommended. Hubby tried various tactics none of which worked. I really appreciate your blog…always great info.

    April 12, 2010 at 6:16 pm

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