# Best way to prevent carpenter bees from boring into exposed lumber **URL:** \ **Category:** In My Humble Opinion\ **Created:** [March 6, 2026, 7:28pm UTC](https://boards.straightdope.com/t/best-way-to-prevent-carpenter-bees-from-boring-into-exposed-lumber/1028264 "2026-03-06T19:28:16Z")\ **Posts on this page:** 8\ **Page:** 1
**Author:** ![Stana\_Claus](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/stana_claus/32/13874_2.png) [@Stana\_Claus](https://boards.straightdope.com/u/Stana_Claus)\ **Post date:** [March 6, 2026, 7:28pm UTC](https://boards.straightdope.com/t/best-way-to-prevent-carpenter-bees-from-boring-into-exposed-lumber/1028264/1 "2026-03-06T19:28:16Z")
Continuing the discussion from [Hey, that hurt? (Wasp Stings)](https://boards.straightdope.com/t/hey-that-hurt-wasp-stings/1028211/33): I’ve read the suggested threads for treating the holes already bored with insecticide and/or sealing the holes, but are there any known methods (short of wrapping the lumber with screening or metal) for deterring them from boring the d@mned hole in the first place? Back in November I built my wife a carport next to our house and I’d like to discourage any carpenter bees from even thinking about defacing it. The posts are pressure treated lumber, but the rafters and purlins are not treated if that matters any. I do know that pressure treatment in and of itself is no deterrent to these critters. So, any suggestions for things available for purchase or effective home remedies will be greatly appreciated. Thanks. ---
**Author:** ![Eric1](https://avatars.discourse-cdn.com/v4/letter/e/3bc359/32.png) [@Eric1](https://boards.straightdope.com/u/Eric1)\ **Post date:** [March 6, 2026, 9:02pm UTC](https://boards.straightdope.com/t/best-way-to-prevent-carpenter-bees-from-boring-into-exposed-lumber/1028264/2 "2026-03-06T21:02:23Z")
That’s kind of hard to take a measure after the carport is built. I’ve painted the lumber as I’ve prepped materials. That seems the most inexpensive way to treat the lumber. I was thinking about spraying the lumber with eucalyptus oil. Where I live by eucalyptus groves, that’s convenient to get but messy to apply. Your question’s really a good one. ---
**Author:** ![Munch](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/munch/32/5281_2.png) [@Munch](https://boards.straightdope.com/u/Munch)\ **Post date:** [March 6, 2026, 9:17pm UTC](https://boards.straightdope.com/t/best-way-to-prevent-carpenter-bees-from-boring-into-exposed-lumber/1028264/3 "2026-03-06T21:17:46Z")
I’ve bought carpenter bee traps, and they managed to get 3-5 bees each year - but it certainly doesn’t get all of them. I end up just spending an hour on the porch with a beer while swatting them with a tennis racket. ---
**Author:** ![Stana\_Claus](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/stana_claus/32/13874_2.png) [@Stana\_Claus](https://boards.straightdope.com/u/Stana_Claus)\ **Post date:** [March 6, 2026, 9:34pm UTC](https://boards.straightdope.com/t/best-way-to-prevent-carpenter-bees-from-boring-into-exposed-lumber/1028264/4 "2026-03-06T21:34:54Z")
I pretty much keep bee traps hung from the eaves of the house and all other structures around the yard. I’ve caught many, many bees in them, but not all of them. I still get bees boring into exposed (usually pressure treated) wood like potting benches, hand rails, garden fences, etc. I’ve also seen things like citrus or peppermint oil being offered for sale for this purpose, but am dubious about their effectiveness. Has anybody here had any success using anything like that? What about spray-on insecticides as a preventative? I’ve seen some places recommending Spectracide Bug Stop or Ortho Home Defence, but those products seem to be more targeted at ants, roaches, and things like that. Would they actually work against carpenter bees? ---
**Author:** ![Beckdawrek](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/beckdawrek/32/3647_2.png) [@Beckdawrek](https://boards.straightdope.com/u/Beckdawrek)\ **Post date:** [March 6, 2026, 10:02pm UTC](https://boards.straightdope.com/t/best-way-to-prevent-carpenter-bees-from-boring-into-exposed-lumber/1028264/5 "2026-03-06T22:02:38Z")
There’s an insecticide you can add to paint or other deck sealing media. I can’t swear by it. I live in a log home and am always living in fear of the critter who would chew, scratch or bore it to dust, happily. So when we sealed the logs the last time we added this stuff to it. After 20 years the house still stands. So maybe it worked. Can’t attest what caused it to stay up. Can’t remember the name of the stuff. I’m sure we bought it at Sherwin Williams. That’s where we bought the sealer. Mostly I believe there’s not enough boring bees working to do too much damage. Yes. Fill holes if you see fit. Cuss the sky and hope for the best. ETA I looked up the stuff. It’s called Bug juice by M1. ---
**Author:** ![Jackmannii](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jackmannii/32/311_2.png) [@Jackmannii](https://boards.straightdope.com/u/Jackmannii)\ **Post date:** [March 6, 2026, 10:50pm UTC](https://boards.straightdope.com/t/best-way-to-prevent-carpenter-bees-from-boring-into-exposed-lumber/1028264/6 "2026-03-06T22:50:13Z")
Standard pyrethrin/pyrethroid sprays work on carpenter bees for a quick kill. I deploy a bunch of traps every year to cut down on their numbers somewhat. Destructive little monsters, they are. ---
**Author:** ![Stana\_Claus](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/stana_claus/32/13874_2.png) [@Stana\_Claus](https://boards.straightdope.com/u/Stana_Claus)\ **Post date:** [March 7, 2026, 12:44am UTC](https://boards.straightdope.com/t/best-way-to-prevent-carpenter-bees-from-boring-into-exposed-lumber/1028264/7 "2026-03-07T00:44:13Z")
Good to know. My grandfather used to use permethrin on his cattle, dogs, and any children that got too close, to control ticks, horn flies, bot flies, and a wide assortment of other critters. Was not aware that it is also (apparently very) effective on bees. I’ll have to see what I can find at our local Co-op or Tractor Supply. It will certainly be worth a try. Thanks. ---
**Author:** ![Crafter\_Man](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/crafter_man/32/458_2.png) [@Crafter\_Man](https://boards.straightdope.com/u/Crafter_Man)\ **Post date:** [March 7, 2026, 2:45am UTC](https://boards.straightdope.com/t/best-way-to-prevent-carpenter-bees-from-boring-into-exposed-lumber/1028264/8 "2026-03-07T02:45:25Z")
We live in a log house. 'Nuf said. I hate those bastards. I have found that carpenter bee traps seem to work, though. Buy 3 or 4 of them.